Electrical circuit for delivering power to consumer electronic devices

ABSTRACT

An electrical circuit for providing electrical power for use in powering electronic devices, such as monitors, televisions, white goods, data centers, and telecom circuit boards, is described herein. The electrical circuit includes an input terminal configured to receive an input power signal, an output terminal configured to provide an output power signal, and a plurality of voltage reduction circuit cells coupled between the input terminal and the output terminal. Each of the voltage reduction circuit cells includes a pair of flyback capacitors, a switching circuit, and a hold capacitor. The switching device is configured to operate the corresponding voltage reduction circuit cell at a charging phase and at a discharging phase. The plurality of voltage reduction circuit cells are configured to deliver the output power signal having a voltage level that is less than the voltage level of the input power signal.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/925,860, filed Oct. 28, 2015, which claims priority to U.S.Provisional Patent Application Ser. No. 62/069,672, filed on Oct. 28,2014, claims priority to U.S. Provisional Patent Application Ser. No.62/074,525, filed on Nov. 3, 2014, claims priority to U.S. ProvisionalPatent Application Ser. No. 62/094,884, filed on Dec. 19, 2014, claimspriority to U.S. Provisional Patent Application Ser. No. 62/175,972,filed on Jun. 15, 2015, claims priority to U.S. Provisional PatentApplication Ser. No. 62/180,549, filed on Jun. 16, 2015, claims priorityto U.S. Provisional Patent Application Ser. No. 62/208,520, filed onAug. 21, 2015, claims priority to U.S. Provisional Patent ApplicationSer. No. 62/236,731, filed on Oct. 2, 2015, all of which are herebyincorporated by reference in their entirety for all purposes.

COPYRIGHT NOTICE

The figures included herein contain material that is subject tocopyright protection. The copyright owner has no objection to thefacsimile reproduction by anyone of this patent document as it appearsin the U.S. Patent and Trademark Office, patent file or records, butreserves all copyrights whatsoever in the subject matter presentedherein.

FIELD OF THE INVENTION

The present invention relates generally to electrical power circuitsand, more particularly, to an electrical power circuit for providingelectrical power for use in charging and/or powering consumer electronicdevices.

BACKGROUND OF THE INVENTION

The Energy Crises Requires Demand Side Response That Lowers CurrentLoads. The Energy Crisis is upon us worldwide. For instance, the U. S.Department of Energy predicts that by 2015 there will not, on theaverage, be enough electric power to supply average demand in the U.S.

One of the controllable offenders is “Vampire Loads”. Also called “WallWart Power” or “Standby Power”, this electricity waste is estimated bythe U.S. Department of Energy (DOE) to be in excess of 100 Billion kWannually, costing over Ten Billion Dollars in wasted energy. VampireLoad producers includes cell phone chargers, lap top chargers, notebookchargers, calculator chargers, small appliances, and other batterypowered consumer devices.

The U.S. Department of Energy said in 2008:

“Many appliances continue to draw a small amount of power when they areswitched off. These “phantom” loads occur in most appliances that useelectricity, such as VCRs, televisions, stereos, computers, and kitchenappliances. This can be avoided by unplugging the appliance or using apower strip and using the switch on the power strip to cut all power tothe appliance.”

According to the U.S. Department of Energy, the following types ofdevices consume standby power:

-   -   1. Transformers for voltage conversion. (Including cell phone,        lap top and notepad, calculators and other battery powered        devices that use wall chargers).    -   2. Wall wart power supplies powering devices which are switched        off. (Including cell phone, lap top and notepad, calculator,        battery powered drills and tools, all of which have wall        chargers and have either completely charged the batteries or are        actually disconnected from the device).    -   3. Many devices with “instant-on” functions which respond        immediately to user action without warm-up delay.    -   4. Electronic and electrical devices in standby mode which can        be awakened by a remote control, e.g., some air conditioners,        audio-visual equipment such as a television receiver.    -   5. Electronic and electrical device which can carry out some        functions even when switched off, e.g., with an electrically        powered timer. Most modern computers consume standby power,        allowing them to be awakened remotely (by Wake on LAN, etc.) or        at a specified time. These functions are always enabled even if        not needed; power can be saved by disconnecting from mains        (sometimes by a switch on the back), but only if functionality        is not needed.    -   6. Uninterruptible power supplies (UPS)

All this means that even when a cell phone, lap top or like device iscompletely charged, current is still flowing, but not accomplishinganything and wasting electricity. More recently manufactured devices andappliances continue to draw current all day, every day—and cost youmoney and add to the Energy Crisis Worldwide.

The National Institute of Standards and Technology (NIST) (a division ofthe U.S. Department of Commerce) through its Buildings TechnologyResearch and Development Subcommittee in 2010 stated its goals forreducing “plug loads,” stating:

“The impact of plug loads on overall consumption is quite significant.For commercial buildings, plug loads are estimated at 35% of totalenergy use, for residential 25%, and for schools 10%.

Opportunities for lowering plug loads include:

-   -   1) more efficient plugged devices and appliances,    -   2) automated switching devices that turn off unused appliances        and reduce “vampire” loads from transformers and other small but        always on appliances, or    -   3) modifying occupant behaviors.

The DOE Level VI Energy Efficiency Regulations are set to go into effectin 2016 requiring that power supplies under 49 watts be no less than 86%efficient across all loads, and have a standby power draw of less than100 milliwatts. The European Commission is predicting similar externalpower supply regulations in 2016.

One of the problems experienced by virtually all modern electronics isthat power supplies, whether external or embedded “power modules”, arenot energy efficient. This is true for a number of reasons, one of whichdates back to 1831 when Michael Faraday invented the transformer.Transformers are inherently inefficient because, as an analog device,they can only produce one power output for each specific winding. So iftwo power outputs are necessary, two secondary windings are necessary.Moreover, there are often over 50 parts and pieces that are necessary towork with a transformer to create a common modern external power supply,the numbers only get somewhat lower with internal or embedded powermodules. The number of parts in a power supply is inherently inefficientbecause current must travel in, around and through the various parts,each with different power dissipation factors; and even the circuittraces cause resistive losses creating energy waste.

Further, the way a transformer works is creating and collapsing amagnetic field. Since all of the electrons cannot be “recaptured” by themagnetic field creation/collapse, those that escape often do so as heat,which is why cell phone, lap top and tablet chargers feel warm or hot tothe touch. It is also the primary reason why all consumer electronicscreate heat, which not only wastes energy/electricity, but causeseventual detrition through heating of other associated electronic parts.

Another inefficiency found in current electronics is the need formultiple internal power supplies to run the different parts. Forinstance, in the modern world power modules, MOSFETS have become a moreand more important part of the “real world” interfaces in circuitry.

Metal-oxide-semiconductor field-effect transistors (MOSFETs) enableswitching, motor/solenoid driving, transformer interfacing, and a hostof other functions. At the other end of the spectrum is themicroprocessor. Microprocessors are characterized by steady reducedoperating voltages and currents, which may be 5 volts, 3.3 volts, 2.7volts or even 1.5 volts. In most systems the MOSFETS and microprocessorsare used together or in combination to make the circuitry work. However,most often the microprocessor and the drivers for the MOSFETS operate atdifferent voltages, causing the need for multiple power supplies withina common electrical device circuit.

A standard high-voltage NMOS MOSFET requires a driver that can deliver agate voltage of 5-20 volts more than that rail voltage to successfullyturn it on and off. In the case of turn on, there is actually arequirement that the gate driver voltage exceed the rail power to beeffective. The other main function of the high-voltage MOSFET gatedriver is to have a reduced input drive requirement making it compatiblewith the output drive capability of modern CMOS processor.

This MOSFET/driver arrangement, common in most external power supplies,like chargers, actually requires three separate power supplies. Thefirst power supply needed is the main power rail, which is normallycomposed of the rectified Line voltage in the range of 127 VDC to 375VDC supplied to the MOSFET. The second power supply needed is the 15volts (or higher) required by the MOSFET drivers. Finally, themicroprocessors require another isolated power supply for their manydifferent and varying voltages.

A good example of the current inefficiencies and energy waste is foundin a typical television, which requires as many as four to six differentpower supply modules to run the screen, backlighting, main circuitboard, and sound and auxiliary boards. This current system requiresmultiple transformers and dozens of parts for each power supply needed.The transformers and the parts (including MOSFETS) multiply heat throughtheir duplicated inefficiencies, which is one reason the back of atelevision is always hot to the touch. In addition, the moretransformers that are needed for various power outputs, the more partsare needed, and more causation for energy waste is created.

In addition to the heat problem, the multiple transformer based powersupplies all need typically from forty to sixty parts to operate,requiring dozens of parts for a typical transformer based televisionpower supply module which increases costs and total component size whiledecreasing reliability. With the multiplicity of parts comes increasedsystem resistance which ends up in wasted energy as heat.

The present invention is aimed at one or more of the problems identifiedabove to provide better efficiencies and create more control overelectrical inrush currents from rail sources.

SUMMARY OF THE INVENTION

In one aspect of the present invention, an electrical circuit forproviding high efficiency electrical power for use in poweringelectronic devices, such as monitors, televisions, white goods, datacenters, and telecom circuit boards, is provided. The electrical circuitincludes an input terminal configured to receive an input power signal,an output terminal configured to provide an output power signal, and aplurality of voltage reduction circuit cells coupled between the inputterminal and the output terminal. Each of the voltage reduction circuitcells includes a pair of flyback capacitors, a switching circuit, and ahold capacitor. The switching device is configured to operate thecorresponding voltage reduction circuit cell at a charging phase and ata discharging phase. The plurality of voltage reduction circuit cellsare configured to deliver the output power signal having a voltage levelthat is less than the voltage level of the input power signal.

In another aspect of the present invention, a method of operating anelectrical circuit for powering electronic devices with high efficiencyand low standby draw is provided. The electrical circuit includes aninput terminal configured to receive an input power signal, an outputterminal configured to provide an output power signal, and a pluralityof voltage reduction circuit cells coupled between the input terminaland the output terminal. Each of the voltage reduction circuit cellsincludes a pair of flyback capacitors, a switching circuit including aplurality of switching devices, and a hold capacitor. The methodincludes determining a voltage level of the input power signal,determining a voltage level of the output power signal, determining again setting for each of the plurality of voltage reduction circuitcells as a function of the voltage level of the input power signal andthe voltage level of the output power signal, and regulating theplurality of voltage reduction circuit cells at the corresponding gainsetting to deliver the output power signal at the corresponding voltagelevel.

In a further aspect of the present invention, an apparatus for providingelectrical power for use in powering electronic devices is provided. Theapparatus includes a plurality of semiconductor chips. Each of theplurality of semiconductor chips includes a voltage reduction circuitthat includes a plurality of capacitor terminals and a switching circuitincluding a plurality of switching devices coupled to the plurality ofcapacitor terminals. The apparatus also includes a plurality of flybackcapacitors coupled to each of the plurality of capacitor terminals. Theplurality of semiconductor chips includes a first semiconductor chipincluding an input terminal configured to receive an input power signaland a second semiconductor chip including an output terminal configuredto provide an output power signal. The plurality of voltage reductioncircuit cells are coupled together in series between the input terminaland the output terminal for delivering the output power signal at avoltage level that is less than a voltage level of the input powersignal.

In one aspect of the present invention, an electrical circuit forproviding electrical power for use in powering electronic devices isprovided. The electrical circuit includes a voltage reduction circuitcell that includes an input terminal configured to receive an inputpower signal, an output terminal configured to provide an output powersignal, a first capacitor, a second capacitor, a switching circuit, anda hold capacitor coupled between the switching circuit and the outputterminal. The switching circuit includes a plurality of switchingdevices that are coupled to the first and the second capacitors fordelivering power from the input terminal to the output terminal. Theplurality of switching devices includes at least two switching devicesthat are coupled to ground. The voltage reduction circuit cell alsoincludes a controller for operating the switching circuit in a pluralityof operational modes to deliver the output power signal at a desiredvoltage level.

In another aspect of the present invention, a method of operating anelectrical circuit for powering electronic devices is provided. Theelectrical circuit includes a voltage reduction circuit cell thatincludes an input terminal, an output terminal, a first capacitor, asecond capacitor, a switching circuit coupled to the first and thesecond capacitors, a hold capacitor coupled between the switchingcircuit and the output terminal, and a controller for operating theswitching circuit. The method includes the steps of receiving an inputpower signal at the input terminal and the controller operating theswitching circuit in a charge mode to couple a positive plate of each ofthe first and the second capacitors to the input terminal and to couplea negative plate of each of the first and the second capacitors to thehold capacitor, and operating the switching circuit in a discharge modeto deliver an output power signal to the output terminal at a desiredvoltage level.

In a further aspect of the present invention, an apparatus for providingelectrical power for use in powering electronic devices is provided. Theapparatus includes a plurality of capacitors and a semiconductor chip.The plurality of capacitors, which, one or more may be either on themonolithic silicon or external, and includes a first capacitor, a secondcapacitor, and a hold capacitor. These capacitors may be the “deeptrench” type in silicone or other types in silicon and externalcapacitors. The semiconductor chip includes an input terminal formed onthe semiconductor chip and configured to receive an input power signal,an output terminal formed on the semiconductor chip and configured toprovide an output power signal, a plurality of capacitor terminalsformed on the semiconductor chip, and a switching circuit formed on thesemiconductor chip. Rectification, if needed, for converting AC input,may either be external to the chip or be on a circuit within theIntegrated Circuit. The inductors referenced in this invention mayeither be external to the IC or incorporated into the IC. The pluralityof capacitor terminals includes a first set of capacitor terminals thatare coupled to the first capacitor, a second set of capacitor terminalsthat are coupled to the second capacitor, and a third set of capacitorterminals that are coupled to the hold capacitor. The switching circuitincludes a plurality of switching devices that are coupled to the firstcapacitor, the second capacitor, and the hold capacitor with theplurality of capacitor terminals. A controller is coupled to theswitching circuit for operating the switching circuit in a plurality ofoperational modes to deliver the output power signal at a desiredvoltage level. The controller may either be an embedded microcontrollercore in the silicone, external chip, or a combination of state machine,analog, digital and microprocessor devices; which may operate with orwithout some type of non-volatile memory (NVM), such as One TimeProgrammable (OTP), Flash memory, or EEprom. The memory may either beembedded on the silicon or external, and may be a die packaged with theASIC.

In one aspect of the present invention, an electrical circuit forproviding electrical power for use in powering electronic devices isprovided. The electrical circuit includes an input terminal configuredto receive an input power signal, an output terminal configured toprovide an output power signal, and a forward converter coupled to theinput terminal and the output terminal. The forward converter includes atransformer, and a primary side regulation circuit coupled to a primaryside of the transformer. The primary side regulation circuit includes aswitching device coupled to the primary side, a current sense circuitconfigured to sense a current level on the primary side, and acontroller configured to generate a pulse-width modulated control signaldelivered to the switching device as a function of the sensed currentlevel to regulate the transformer to deliver the output power signal ata desired voltage level.

In another aspect of the present invention, a method of operating anelectrical circuit for powering electronic devices is provided. Theelectrical circuit includes an input terminal configured to receive aninput power signal, an output terminal configured to provide an outputpower signal, and an optional forward converter coupled to the inputterminal and the output terminal. The forward converter includes atransformer and a primary side regulation circuit including a controllerand a switching device coupled to a primary side of the transformer. Themethod includes the steps of sensing a current level of the primary sideof the transformer, generating a pulse-width modulated control signal asa function of the sensed current level, and transmitting the pulse-widthmodulated control signal to the switching device to operate theswitching device to regulate the input to the transformer to deliver theoutput power signal at a desired voltage level.

In a further aspect of the present invention, an apparatus for providingelectrical power for use in powering electronic devices is provided. Theapparatus includes a transformer for receiving an input power signal anddelivering an output power signal, a capacitor coupled to a primary sideof the transformer and to ground, the capacitor configured to reset thetransformer after each transformer cycle, and a semiconductor chip whichmay have one or more circuits external to the semiconductor chip (IC).The semiconductor chip includes a transformer terminal formed on thesemiconductor chip, a switching device formed on the semiconductor chipand coupled to the primary side of the transformer with the transformerterminal, and a controller formed on the semiconductor chip. Thecontroller is configured to sense a current level of the primary side ofthe transformer and generate a pulse-width modulated control signaldelivered to the switching device as a function of the sensed currentlevel to regulate the transformer to deliver the output power signal ata desired voltage level.

The electrical circuit may also includes a vampire load eliminationsystem that is configured to determine when a consumer device hasfinished charging and/or is disconnected from the power circuit, andoperates the power circuit to disconnect the supply of power to thepower circuit and/or the electronic device, and also capable of creatinga flea powered “stand-by” mode. This is accomplished by putting thesystem in to “sleep mode” where the only circuits powered are the timingcircuits, which periodically “wake up” to check to see if there is aconnection or current draw on the secondary.

In another aspect of the invention, the power circuit is formed on asemiconductor chip that includes analog and digital components on thesame chip. A semiconductor process such as a 350V Silicon-on-Insulator(SoI) BCD process could be used for the semiconductor, which wouldpermit the integration on one die of the microcontroller, timer/quartzreal-time clock, PID controller and PWM controllers, MOSFETs, andcorresponding drivers. In addition, the typical specific capacitance inCMOS technology ranges from 0.1 fF/μm² (polypoly capacitors) to 5 fF/μm²(MIM capacitors) or ceramic capacitors can be considered. Moreover, aprocess like DMOS can be used, or a bi/substrate can be considered, suchas a layer of Silicon Carbonate, with Gallium Nitrate or Silicon Dioxidebi/substrata's also can be used. Or alternatively, Gallium Nitrate orGallium Arsenide and the use of Deep Trench capacitors could be used forconstruction of the chip or the transistors within the chip rather thanCMOS silicon. All of these options are necessary because of thecapacitance needed with the low R_(on) MOSFETS or transistors.

A BCDMOS process may be used to manufacture the power circuit. BCDMOSincludes a process for integrating Bipolar (analog), CMOS (logic) andDMOS (power) functions on a single chip for ultra high voltage (UHV)applications. BCDMOS provides a broad range of UHV applications such asLED lighting, AC-DC conversion and switched mode power supplies. Capableof operating directly “off line” from a 110/220 VAC source, integratedcircuits (ICs) implemented with a non-Epi process can deploy optimized450V/700V DR-LDMOS transistors that specify low on resistance and abreakdown voltage that exceeds 750V. When used in power switchingapplications, designers can expect lower conduction and switchinglosses.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a schematic diagram of an electronic charging device for usein providing electrical power to electronic devices, according to anembodiment of the present invention;

FIG. 2 is a block diagram of a power circuit that may be used with thecharging device shown in FIG. 1, for use in providing electrical powerto electronic devices, according to an embodiment of the presentinvention;

FIG. 3 is a schematic diagram of a buck regulator circuit that may beused with the power circuit creating a “Hybrid” voltage divider circuitas shown in FIG. 2, according to an embodiment of the present invention;

FIGS. 4-7 are schematic diagrams of a switch capacitor voltage dividercircuit that may be used with the power circuit shown in FIG. 2,including the sharing of gates between capacitors for further reducingRDS_(ON) losses, according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a portion of the switch capacitorvoltage divider circuit, herein referred to as a Muxcapacitor™ (Mux)Core Cell, shown in FIG. 4, according to an embodiment of the presentinvention;

FIG. 9 is a table illustrating gain settings for use with the switchcapacitor voltage divider circuit shown in FIG. 8, according to anembodiment of the present invention;

FIGS. 10-12 are schematic illustrations of the switch capacitor voltagedivider circuit shown in FIG. 8 in a charge phase mode and a dischargephase mode associated with each of the gain settings shown in FIG. 9,according to an embodiment of the present invention;

FIG. 13 is a schematic diagram of a forward converter circuit that maybe used with the power circuit shown in FIG. 2, according to anembodiment of the present invention;

FIG. 14 is a schematic diagram of an alarm control circuit that may beused with the power circuit shown in FIG. 2, according to an embodimentof the present invention;

FIGS. 15A and 15B are schematic diagrams of the power circuit shown inFIG. 2, including a power controller integrated circuit, according to anembodiment of the present invention;

FIGS. 16, 17A, and 17B are block diagrams of the power controllerintegrated circuit shown in FIG. 10, according to embodiments of thepresent invention;

FIG. 18 is a block diagram of a power management unit that may be usedwith the power controller integrated circuit shown in FIGS. 16, 17A, and17B, according to an embodiment of the present invention;

FIG. 19 is a graphic illustration of Power-On-Reset threshold voltagesthat may be used with the power controller integrated circuit shown inFIGS. 16, 17A, and 17B;

FIG. 20 is a schematic illustration of a Proportional to Integral andDifferential Regulator Control circuit that may be used with the powercontroller integrated circuit shown in FIGS. 16, 17A, and 17B, accordingto an embodiment of the present invention;

FIGS. 21 and 22 are block diagrams of a digital control block that maybe used with the power controller integrated circuit shown in FIGS. 16,17A, and 17B, according to embodiments of the present invention;

FIG. 23 is a flow chart illustrating a method of operating the powercircuit shown in FIG. 2 for use in providing electrical power toelectronic devices, according to an embodiment of the present invention;

FIG. 24 is a graphic illustration of state transitions that may be usedwith the method shown in FIG. 23, according to an embodiment of thepresent invention;

FIG. 25 is a schematic illustration of a communication interface thatmay be used with the power controller integrated circuit shown in FIGS.16, 17A, and 17B, according to an embodiment of the present invention;

FIG. 26 is a schematic illustration of a microprocessor communicationprotocol that may be used with the power controller integrated circuitshown in FIGS. 16, 17A, and 17B, according to an embodiment of thepresent invention;

FIG. 27 is an illustration of a timing diagram an Inter-IntegratedCircuit that may be used with the power controller integrated circuitshown in FIGS. 16, 17A, and 17B, according to an embodiment of thepresent invention;

FIGS. 28 and 29 are schematic illustrations of the power circuit shownin FIG. 2, according to an embodiment of the present invention;

FIG. 30 is a connection diagram that may be used with the powercontroller integrated circuit shown in FIGS. 16, 17A, and 17B, accordingto an embodiment of the present invention;

FIGS. 31 and 32 are additional schematic illustrations of the powercontroller integrated circuit shown in FIGS. 16, 17A, and 17B, accordingto embodiments of the present invention;

FIG. 33 is a flow chart of an algorithm for a low-current detection andan error detection that may be used with the power controller integratedcircuit shown in FIGS. 16, 17A, and 17B, according to an embodiment ofthe present invention;

FIGS. 34 and 35 are schematic illustrations of the power circuit shownin FIG. 2, according to an embodiment of the present invention;

FIG. 36 is a schematic illustration of Level Shifter that may be usedwith the power circuit shown in FIG. 2, according to an embodiment ofthe present invention;

FIG. 37 is a schematic illustration of an RCD circuit that may be usedwith the forward converter circuit shown in FIG. 13, according to anembodiment of the present invention;

FIGS. 38 and 39 are additional schematic illustrations of the powercircuit shown in FIG. 2, according to an embodiment of the presentinvention;

FIG. 40 is a schematic illustration of a portion of the power circuitshown in FIG. 2, according to an embodiment of the present invention;

FIG. 41 is another schematic illustrations of the power circuit shown inFIG. 2, according to an embodiment of the present invention.

FIGS. 42-50 are additional schematics diagram of the electrical powercircuit shown in FIG. 2, according to various embodiments of the presentinvention;

FIG. 51 is another schematic diagram of a voltage reduction circuit cellshown in FIG. 8 that may be used with the electrical power circuit shownin FIGS. 2 and 42-50, according to an embodiment of the presentinvention;

FIGS. 52-55 are schematic diagrams of the voltage reduction circuit cellwith a 1× gain setting, according to an embodiment of the presentinvention;

FIGS. 56-59 are schematic diagrams of the voltage reduction circuit cellwith a ⅔× gain setting, according to an embodiment of the presentinvention;

FIGS. 60-63 are schematic diagrams of the voltage reduction circuit cellwith a ½× gain setting, according to an embodiment of the presentinvention;

FIGS. 64 and 65 are schematic diagrams of the voltage reduction circuitcell in a bypass mode, according to an embodiment of the presentinvention;

FIG. 66 is a schematic diagram of a buck regulator buck regulatorcircuit that may be used with the power circuit shown in FIGS. 2 and42-50, according to an embodiment of the present invention;

FIG. 67 is a schematic diagram of the voltage reduction circuit cell,herein referred to as a Bux™ circuit, shown in FIGS. 8 and 51 includingan integrated buck regulator circuit, according to an embodiment of thepresent invention;

FIG. 68 is a flowchart of a method of operating an electrical circuitfor powering electronic devices that may be used with the electricalpower circuit shown in FIGS. 2 and 42-50, according to an embodiment ofthe present invention;

FIGS. 69 and 70 are exemplary illustrations of data records that may beused by a controller for use in operating the electrical power circuitshown in FIGS. 2 and 42-50, according to an embodiment of the presentinvention;

FIGS. 71 and 72 are schematic illustrations of a primary side regulationcircuit that may be used with the electrical power circuit shown inFIGS. 2 and 42-50, according to an embodiment of the present invention;

FIG. 73 is a block diagram illustrating a portion of a controller thatmay be used with the primary side regulation circuit shown in FIGS. 71and 72, according to an embodiment of the present invention;

FIG. 74 is another schematic illustration of a primary side regulationcircuit that may be used with the electrical power circuit shown inFIGS. 2 and 42-50, according to an embodiment of the present invention;

FIGS. 75 and 76 are flowcharts of methods of operating an electricalcircuit for powering electronic devices with the primary side regulationcircuit shown in FIGS. 71 and 72, according to an embodiment of thepresent invention;

FIG. 77 is a graphical plot illustrating timing relationships associatedwith operational parameters of the operation parameters the primary sideregulation circuit shown in FIGS. 71 and 72, according to an embodimentof the present invention;

FIGS. 78 and 79 are exemplary illustrations of data records that may beused by a controller for use in operating an electrical power circuitwith the primary side regulation circuit shown in FIGS. 71 and 72,according to an embodiment of the present invention;

FIG. 80 illustrates a Primary Side Regulation, PSR-LV or HLV-PSR digitalop level state diagram, according to an embodiment of the presentinvention;

FIG. 81 illustrates a Primary Side Regulation, control loop partition,according to an embodiment of the present invention;

FIG. 82 is a conceptual diagram of the digital Primary Side Regulationcontrol loop, according to an embodiment of the present invention;

FIG. 83 is a conceptual diagram of the digital Primary Side Regulationexecution processing time line, according to an embodiment of thepresent invention;

FIG. 84 is a block diagram of a 8051 digital subsystem that may be usedwith the Primary Sider Regulation system, according to an embodiment ofthe present invention; and

FIG. 85 is a block diagram of a 80251 digital sub system that may beused with the Primary Sider Regulation system, according to anembodiment of the present invention.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DETAILED DESCRIPTION OF INVENTION

With reference to the drawings and in operation, the present inventionovercomes at least some of the disadvantages of known power deliverysystems by providing a power module that includes a power circuit thatprovides DC voltage output power to consumer electronic devices from anAC mains supply (typically 120 VAC (US) to 240 VAC[EU/Asia]). The powercircuit is configured to provide electrical power to charge electronicstorage devices and/or power consumer electronic products including, butnot limited to, a cell phone, a smartphone, a tablet computer, a laptop,and/or any suitable electronic device that may benefit from thisinvention due to extremely high efficiencies and very low stand-by powerrequirements.

In an embodiment of the present invention, the power circuit includes aplurality of voltage reduction circuit cells, e.g., stages, that areconfigured to receive an input power signal and deliver an output powersignal at a desired voltage level. In one embodiment, each voltagereduction circuit cell includes a pair of flyback capacitors, aswitching circuit that is coupled to the flyback capacitors and includesa plurality of switching devices, a hold capacitor coupled between theswitching circuit and an output terminal, and a controller that isconfigured to operate the switching circuit in a plurality ofoperational modes to deliver the output power signal at a desiredvoltage level. In addition, the controller may be configured to operateeach voltage reduction circuit cell in capacitive isolation tofacilitate preventing a corresponding input terminal from beingconnected directly to the corresponding output terminal of the voltagereduction circuit cell during operation between a charge mode and adischarge mode.

In one embodiment, the power circuit may include a buck regulatorcircuit coupled to the plurality of voltage reduction circuit cells. Inanother embodiment, the power circuit may include a forward converterincluding a transformer that is coupled to the plurality of voltagereduction circuit cells. The power circuit may also include a primaryside regulation circuit that is coupled to a primary side of thetransformer to regulate the transformer to deliver the output powersignal at a desired voltage level. In one embodiment, the primary sideregulation circuit includes a switching device that is coupled to theprimary side of the transformer, a current sense circuit that isconfigured to sense a current level on the primary side, and acontroller that is configured to generate a pulse-width modulatedcontrol signal delivered to the switching device as a function of thesensed current level to regulate the transformer to deliver the outputpower signal at a desired voltage level.

In another embodiment of the present invention, the power circuitincludes a primary power circuit and a secondary power circuit forreceiving high voltage AC power from an electrical power source anddelivering a low voltage DC power signal to one or more electronicdevices. The primary power circuit receives the AC power signal from anAC power supply and generates an intermediate direct current (DC) powersignal at a reduced voltage level. The secondary power circuit receivesthe intermediate DC power signal from the primary power circuit andgenerates and delivers an output DC power signal having a voltage levelsuitable for use in powering and/or charging consumer electronicdevices.

The primary power circuit includes a rectification circuit for receivingthe AC power signal and generating a rectified DC power signal, and aswitch capacitor voltage divider circuit for dividing the rectified DCvoltage to a reduced voltage for use by the secondary power circuit. Theswitch capacitor voltage divider circuit includes fly-back capacitors tomaximize power efficiency and a hold capacitor to minimize the voltageripple. In one embodiment, the switch capacitor voltage divider circuitis configured to deliver up to 50 mA and maintain ≧95% efficiency acrossthe range of load currents from 50 mA to less than 1 mA under light loadconditions. The primary power circuit may also include a switch-modebuck regulator that is connected in parallel with the switch capacitorvoltage divider circuit for handling large current loads, for example,up to 430 mA to 500 mA (or more) of current. The buck regulator mayinclude a P-channel MOSFET switch, a high voltage buck diode, and a buckenergy storage inductor. In addition, the buck regulator may alsoinclude a pulse-width modulator (PWM) controller for generating a pulsewidth modulated signal to control the on/off time of the buck regulatorPMOSFET, which may also be expressed as an NMOSFET with the appropriategate drivers.

The secondary power circuit includes a forward converter power circuitthat includes a transformer for receiving the intermediate DC powersignal from the primary power circuit and generating the output DC powersignal. The forward converter also includes a MOSFET connected to theprimary side of the transformer, which may either be internal orexternal to the IC, and a control circuit to operate the MOSFET toregulate the voltage at the output of the forward converter as loadcurrent is drawn from the secondary-side of the transformer. Forexample, the forward converter control loop may be configured toregulate the output voltage under heavy fluctuation (4.5 nA to 4.5 A) ofload current without triggering any instability.

In the modern world, the MOSFET has become a more and more importantpart of “Real World” interfaces. It enables motor/solenoid driving,transformer interfacing, and a host of other functions. At the other endof the spectrum is the Microprocessor. It is characterized by steadilyreduced operating voltages and currents. In many systems these parts areused together. A standard high-voltage MOSFET requires a driver that candeliver on the order of a 5 v to 20 v volt swing to the FET gate inorder to successfully turn the FET on or off. In the case of turn-on foran NMOSFET, it is actually required that this gate drive voltage exceedthe power rail voltage. Specialty drivers using charge pump technologyhave been devised for this purpose, but they are typically discreteparts and increase the number of power rails needed on a circuit. TheFET driver's other main function is to have a reduced input voltagerequirement making it compatible with the output port capability of amodern CMOS microprocessor. This arrangement is costly in terms of powerand typically requires three power supplies. First is the main powerrail. It is composed of a voltage in the range of 100 to 600 voltssupplied to the MOSFET. The second supply is the 5-20 volts required bythe driver and finally is the supply required by the microprocessor.This present invention combines all these rails within the chip, suchthat the power and parts normally associated with the circuit areminimized and therefore efficiencies increased.

In many circumstances, the power supplies constitute a significantpercentage of both the parts count and cost in a small system. Aconsolidated part can substantially alter this equation. This new partwould consist of a combination of a high power MOSFET as the base partto which is added the appropriate driver with an included charge pump.Also added is the power supply required for the driver derived from themain rail supply internally. A final addition is an output pin to supplypower for the microprocessor from this internal supply. In many modestsystems the complete parts list would consist of this new device, themicroprocessor, and the main power rail parts. This would allow the nextgeneration of low cost/low assembly count microprocessor subsystems.

The power module includes the advanced power supply system on a chip(Tronium™ PSSoC), which is the subject of this present invention,including a controller application specific integrated circuit (ASIC) toprovide a low-cost, highly efficient means to convert the AC linevoltage present at a typical home or business electrical outlet to areduced regulated DC voltage for consumer electronic applications.Typical applications include, but are not limited to, charging systemsfor cell-phones, tablets or other handheld devices, USB powerconversion, power supplies for consumer, medical and industrial devices,and many other possible uses.

The Tronium PSSoC™ is configured for use in two primary power moduleapplications including an Autonomous Power Module and a Universal PowerModule. The Autonomous Power Module operates in an autonomous mode ofoperation that is based upon an analog feedback approach for reducedcost. The Universal Power Module operates in a universal mode ofoperation that utilizes a microprocessor (μP) controller and may usesome type of memory, to automatically trim, to provide feedback forregulation of the final output voltage, which can be one power railwhich is controlled/monitored or more, to provide overhead for the statemachine and its regulation algorithms, and to enhance the sleep/wake upmode, as shown in FIG. 23. Some key features of the Tronium PSSoCinclude, but are not limited to, 90 VAC to 264 VAC Line VoltageOperation (other input voltage either AC or DC may be used), a CountryCode located in the controller, which sensing which country's grid isproviding the input, and then automatically sets the algorithms tooperate on that Country's grid, to make the proper divisions of theinput to the target output. Other features also include ProgrammableOutput Voltage (also done by manually or automatically changing thevoltage conversion algorithms to change the target voltage), Hybridswitch capacitor voltage breakdown circuit (i.e., the switch capacitorvoltage divider circuit) & Switch-Mode Buck Regulator (which issynchronously rectified for efficiency) for DC-DC Conversion, PIDRegulation Control Loop for High Accuracy, Digital State Machines forCurrent and Temperature Monitoring, Ultra-Low Power Dissipation for Idle(Vampire) Mode of Operation, Opto-Isolated Microprocessor Interface forConfiguration and Control, I2C Slave Port for Manufacturing Test,auto-detect input voltage range: 127 VDC to 373 VDC (world-wide voltages110 VAC-260 VAC), featured Out Power: 22.5 W (any wattage possible),hybrid voltage converter for high-efficiency operation, stacked SwitchCapacitor Voltage Breakdown Modules, PID regulation loops with PWM gatedrivers, power scaling function for high efficiency at multiple loadlevels and flea power Stand-by Mode, thermal sensing and shut-off, shortcircuit and over-current protection, adjustable no-load/light loadshut-off with restart and control logic, selectable analog or digitalcontrol, minimal or no external circuitry part count and discrete devicesize, and optional digital interface for bi-directional communication.

In addition, the Switch Mode Buck Regulator circuit may include what istypically know as a Buck/Boost circuit; or the Buck/Boost may bereplaced with a SEPIC, Cúk, or Push Pull or other topologies. These willhave synchronous rectification for efficiency and may either use afly-back or forward convertor typologies.

The Tronium PSSoC is an advanced power controller integrated circuitthat is configured to provide output voltage regulation withhigh-efficiency and high accuracy. The advanced features of the TroniumPSSoC provide the user with a multi-purpose device which can be used ina large variety of applications in either a “charger” mode or “constantsupply” mode. Programmable output voltages (1.7V to 48V or higher) arepossible with the Tronium PSSoC, with little or no loss of efficiencyacross a variety of current load conditions, which feature is called the“Dial-a-Voltage” feature. In addition, multiple output currents may becreated by the combination of the Hybrid Circuit, or the SwitchCapacitor Circuit by itself, so as to create multiple voltage/currentcombinations ranging typically from 1.7V to 48V, which is sufficient topower most electronic devices. This “Dial-a-Voltage” feature, is factoryprogrammable or programmable by a customer with a proper code, so thatthe same chip may be used for a 1.7V output or a 48V output by changingthe voltage division algorithms, with only nominal changes in anyexternal components like the transformer winding and the FETs whichdrives the transformer.

The Tronium Power Supply System on a Chip (PSSoC) ASIC is an advancedpower control device that enables high efficiencies across a very widerange of output power. While typical ‘high efficiency’ power supplycontrollers boast ˜50% efficiencies down to 10% of full load, theTronium device is intended to provide >90% efficiency down to and below1% of full load.

The Tronium PSSoC provides a revolutionary topology for high voltagepower conversion by implementing an intermediary voltage rail, allowingthe power capabilities of the system to scale with the load demand. Italso shrinks parts into the ASIC, minimizing external parts needed; andenables a wider range of transformer options for enhanced optimizationof power with lower coil losses. The Tronium PSSoC also provides a PIDswitching controller with which to drive the primary side of atransformer if isolation is required, or other topologies of conversionand regulation. It also features either secondary or primary sidecontrol/feedback.

In one embodiment, the Tronium PSSoC uses a proprietary high-voltageintermediate voltage capacitor voltage breakdown conversion scheme,which can be used alone, or in combination with a switch-mode buckregulator to maintain high-efficiency regardless of the load voltage orcurrent. When no current is being drawn by the load, the device willenter a low-current mode of operation of approximately ½ milliwatt inorder to minimize and virtually eliminate the traditional ‘vampire’current required to stay awake.

The Tronium PSSoC may include the following major circuit blocks:Intermediate Capacitor Voltage Break-Down Converter Module (CVBD Module)(can be one or more stages for desired current output); High-VoltageSingle-Stage or Two-Stage switch capacitor voltage divider circuit;Proportional to Integral and Differential (PID) Regulator Control Blockfor PWM Control of Forward converter; Switch-Mode Buck Regulator PIDController (optional Hybrid typology for voltage output); Buck RegulatorSwitch Driver; Current and Temperature Sense Blocks; 12-bit ADC forVoltage and Current Monitoring; 10-bit DAC's for Feedback Control;Digital Control Block for Current Monitoring State Machine; Serial Inputfor Opto-Isolator Communications Interface; I2C Serial Interface Portfor Test, Evaluation, Repair and Communication; Oscillators forgeneration of internal clock signals; Power Manager for On-Chip Voltageand Current Generation; Adapted for use with or without amicrocontroller which can be embedded into the chip or external; PrimarySide Sensing or Secondary Side Sensing Capabilities; and Synchronousforward convertor.

The power module may also include a Tronium PSSoC that includes bothanalog and digital control in order to optimize performance andefficiency. In order to enable not only analog control but also digitalcontrol the proper inputs and outputs must be available on the TroniumPSSoC. Given these availabilities, and coupled with power loop controlfrom an internal clock—control of the clock can be driven and controlledwith external signals. The novel approach is that these signals can bedriven from the secondary side while the Tronium PSSoC sits on theprimary side of the transformer.

Digital control is commonly accomplished on the same side of theisolation barrier. However, given that the Tronium PSSoC is inherentlyan isolated system, and end to end efficiency optimization is required,control from primary side or secondary back to primary side may beutilized. This is accomplished in a number of different ways given theTronium implementation. This can be done with optocouplers transmittingthe digital control signal from a microcontroller as well as analogsignals from a current sense circuit. Furthermore, this can beaccomplished by using a third winding on the isolation transformer.

Some or all of the circuits and/or electrical devices include in thepower circuit may be integrated onto the chip using either a siliconprocess, Gallium nitride (GaN) or Gallium Arsenide (GaA), or by usingDeep Trench Capacitors, or other available processes which provides highefficiency parts, if high efficiency is desired. Thus, one or all ofthese parts may be embedded in the ASIC rather than be externaldiscretes, even the transformer, using the known transformer in silicon(or GaN-GaA) techniques. In addition, the use of MIM and MOM capacitorsalong with low RDS_(ON) MOSFETS, integrated decoupling capacitors and/orflying capacitors (C_(FLY)), for ripple reduction, which in turndecreases the size of needed capacitors may be used where capacitors orFETS are called for herein. Also, the introduction of integratedinductors on chip helps achieve the highest efficiencies. Alternatively,the highest efficiency parts, like GaA, GaN or Schottky diode parts areto be used.

In addition, the capacitors may be nano-capacitors, and may be basedupon ferroelectric and core-shell materials as well as those based onnanowires, nanopillars, nanotubes, and nanoporous materials.

The substrata for the Tronium PSSoC could be made from customary filmscurrently used in capacitors (if external) or within semiconductorsubstrates such as high or low Ohmic silicon substrate, polysilicon,gallium nitride, gallium arsenide, silicon germanium or substances likesilicon carbide or indium phosphide.

They key is on-board ASIC integration of as many discretes as possiblewhere the process permits, and if efficiency is key then identificationof low RDSon values, high efficient parts, and sufficient voltagebreak-down parts. Another key is to run the Switch Buck Module at higherfrequencies, so that parts become smaller, and sufficiently smaller tobecome on-board chip devices.

A selected embodiment of the present invention will now be explainedwith reference to the drawings. It will be apparent to those skilled inthe art from this disclosure that the following description of theembodiment of the present invention is provided for illustration onlyand not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

FIG. 1 is a schematic diagram of an electronic charging device 10 foruse in providing electrical power to electronic devices. FIG. 2 is ablock diagram of a power module 12 that may be used with the electroniccharging device 10. In the illustrated embodiment, the electroniccharging device 10 includes a housing 14, a pair of power prongs 16extending outwardly from the housing 14 and a device connection assembly18 that is adapted to connect to an electronic device 20 to deliverelectric power from the charging device 10 to the electronic device. Theelectronic charging device 10 also includes the power module 12 thatincludes a power circuit 22 that is configured to receive power from anelectrical power source 24 and deliver power to the electronic device 20such as, for example, portable consumer electronic devices including,but not limited to, a cell phone, a smartphone, a tablet computer, alaptop, and/or any suitable electronic device. In addition, the powercircuit 22 may deliver power for use in charging electronic storagedevices such as, for example, mobile phone/laptop/tablet power storagebatteries. In one embodiment, the power circuit 22 may be configured toprovide low voltage DC output (typically 5 VDC) from an AC mains supplytypically 120 VAC (US) to 264 VAC (EU/Asia).

In the illustrated embodiment, the power circuit 22 includes a primarypower circuit 26 and a secondary power circuit 28. The primary powercircuit 26 is adapted to be electrically coupled to the electrical powersource 24 and is configured to receive an AC (or DC) input power signalfrom the electrical power source 24 and generate an intermediate directcurrent (DC) power signal. The intermediate DC power signal beinggenerated at a first voltage level that is less than a voltage level ofthe AC input power signal. The secondary power circuit 28 iselectrically coupled to the primary power circuit 26 and is configuredto receive the intermediate DC power signal from the primary powercircuit 26 and deliver an output DC power signal to the electronicdevice 20. The output DC power signal is delivered at an output voltagelevel that is less than the first voltage level of the intermediate DCpower signal. For example, in one embodiment, the primary power circuit26 is configured to receive the AC input signal having a voltage levelbetween a range of 127 volts to 375 volts AC and to deliver theintermediate DC power signal at a voltage level of approximately 110volts DC. The secondary power circuit 28 is configured to receive theintermediate DC power signal and deliver the output DC power signal atapproximately 5 volts DC.

In the illustrated AC-DC embodiment, the primary power circuit includesa rectifier circuit 30, an intermediate voltage converter 32, a buckregulator 34, and a hold capacitor 36 that is electrically coupled tothe intermediate voltage converter 32 and the buck regulator 34. Theintermediate voltage converter 32 and the buck regulator 34 are coupledin parallel between the rectifier circuit 30 and the secondary powercircuit 28. The rectifier circuit 30 is configured receive the AC powerinput signal from the electrical power source 24 and generate arectified DC power signal that is delivered to the intermediate voltageconverter 32 and the buck regulator 34. In one embodiment, the rectifiedDC power signal is delivered having a voltage level that isapproximately equal to the voltage level of the AC input power signal.As shown in FIGS. 13, 15A, and 15B, in the illustrated embodiment, therectifier circuit 30 includes a plurality of diodes 38 that are arrangedin a full-wave bridge rectifier having first and second input terminalscoupled to the high and low sides of the electrical power source 24 forproducing a DC power signal from an AC input power signal. In oneembodiment, the rectifier circuit 30 may also include a filter capacitor40 that is coupled to the full-wave bridge rectifier. In yet anotherembodiment, the rectifier circuit 30 does not include the filtercapacitor 40. In another embodiment, the rectifier circuit 30 mayinclude a half-bridge rectifier (not shown).

FIG. 3 is a schematic diagram of the buck regulator circuit 34 that maybe used with the power circuit 22. In the illustrated embodiment, thebuck regulator circuit 34 includes a regulator switch assembly 42 thatis coupled to a voltage reduction circuit 44. The voltage reductioncircuit 44 includes a high voltage buck diode 46, a buck energy storageinductor 48, and a capacitor 50. The regulator switch assembly 42 isoperated to selectively deliver the rectified DC power signal to thevoltage reduction circuit 44. In the illustrated embodiment, theregulator switch assembly 42 includes a P-channel MOSFET 52, a drivercircuit 54 that is coupled to the P-channel MOSFET 52, and a levelshifter 56 that is coupled to the driver circuit 54. In one embodimentthe regulator switch assembly 42 may include an N-channel MOSFET and/ora P-channel MOSFET. In the illustrated embodiment, the buck regulator 34also includes a regulator control circuit 58 that includes a regulatorPWM controller 60 (also shown in FIGS. 16, 17A, and 17B) for generatinga pulse width modulated signal to control P-channel MOSFET 52. In oneembodiment, the control circuit 58 may also include a voltage sensingcircuit 62 that is connected to the primary side of the forwardconverter transformer for sensing the voltage level of the intermediateDC power signal being delivered to the secondary power circuit 28. Theregulator PWM controller 60 may generate a pulse-width modulated controlsignal as a function of the sensed first voltage level to adjust a dutycycle of the PWM control signal being delivered to the P-channel MOSFET52 to maintain the voltage level of the intermediate DC power signal.The Buck Regulator servo loop 58 is voltage controlled and the Vprimaryis sensed and used to modulate the duty cycle of the driver 54.

In one embodiment, the sensing circuit 62 includes one or more HallEffect sensors that are coupled to the primary side of the forwardconverter transformer for sensing a magnetic field being generatedwithin the transformer. The Hall Effect sensors facilitate determining azero-crossing of the transformer by directly sensing the magnetic fieldbeing generated by the transformer during operation. In one embodiment,the sensing circuit 62 includes a primary side Hall Effect sensorcoupled to the primary side of the transformer. The primary side HallEffect sensor is connected to the PWM controller 60 for transmitting asignal to the PWM controller 60 for use in determining when thetransformer nears the “zero-crossing”. In another embodiment, thesensing circuit 62 includes a secondary side Hall Effect sensor that iscoupled to the secondary side of the transformer, and is connected tothe forward converter controller (shown in FIG. 13) for transmitting asignal indicative of the transformer magnetic field for use indetermining the time at which the transformer reaches the“zero-crossing”.

FIGS. 4-8 are schematic diagrams of the intermediate voltage converter32 including a voltage reduction circuit cell. FIG. 9 is a tableillustrating gain settings that may be used with the intermediatevoltage converter 32. FIGS. 10-12 are schematic illustrations of theintermediate voltage converter 32 in a charge phase mode 66 and adischarge phase mode 68 for each of the gain settings shown in FIG. 9.In the illustrated embodiment, the intermediate voltage converter 32includes a single-stage switch capacitor voltage divider circuit that iscoupled to the hold capacitor 36 and the secondary power circuit 28. Theswitch capacitor voltage divider circuit includes a pair of flybackcapacitors 70 that are electrically coupled in parallel and a pluralityof switch assemblies 72 that are electrically coupled to each of theflyback capacitors 70. The switch assemblies 72 are selectively operatedbetween the charge phase mode 66 and the discharge phase mode 68. Duringthe charge phase mode 66 the switch assemblies 72 are operated to form acharging circuit 74 to connect the flyback capacitors 70 to therectifier circuit 30 to deliver the rectified DC power signal to each ofthe flyback capacitors 70. During the discharge phase mode 68, theswitch assemblies 72 are operated to form a discharging circuit 76 toconnect the flyback capacitors 70 to the secondary power circuit 28 todeliver the intermediate DC power signal to the hold capacitor 36.

In one embodiment, as shown in FIG. 8, the single-stage switch capacitorvoltage divider circuit 32 may include a first flyback capacitor Cfb1and a second flyback capacitor Cfb2, and nine switch assemblies S1, S2,S3, S4, S5, S6, S7, S8, and S9. In addition, two of the switchassemblies S3 and S9 are coupled to ground. During operation, the gainsetting of the switch capacitor voltage divider circuit may be adjustedby selectively operating the switch assemblies according to the gainsetting table shown in FIG. 9. For example, during the charge phase mode66 (Phase 1), switches S1, S4, S7, and S8 are turned on and moved to aclosed position and switch assemblies S2, S3, S5, S6, and S9 are turnedoff and moved to an open position to form the charging circuit 74 toconnect the flyback capacitors Cfb1 and Cfb2 to the rectifier circuit30. As shown in FIG. 10-12, in the charging circuit 74 the top plate ofeach flyback capacitor Cfb1 and Cfb2 are connected to the rectifiercircuit 30 line voltage, Vline. For a gain setting equal to G=1×, duringthe discharge phase mode 68 (Phase 2), switch assemblies S2, S3, and S7are turned on and switch assemblies S1, S4, S5, S6, S8, and S9 areturned off to form a discharging circuit 76 shown in FIG. 10 thatincludes the top plate of capacitor Cfb1 connected to the hold capacitor36 and the top plate of capacitor Cfb2 connected to the bottom plate ofcapacitor Cfb1. With reference to FIGS. 9 and 11, for a gain settingequal to G=½×, during the discharge phase mode 68 (Phase 2), switchassemblies S2, S5, and S9 are turned on and switch assemblies S1, S3,S4, S6, S7 and S8 are turned off to form a discharging circuit 76 thatincludes the top plate of capacitor Cfb1 connected to the hold capacitor36, the bottom plate of capacitor Cfb1 connected to ground, and the topplate of capacitor Cfb2 connected to the hold capacitor 36, the bottomplate of capacitor Cfb2 connected to ground. Referring to FIGS. 9 and12, for example, a gain setting equal to G=⅔×, during the dischargephase mode 68 (Phase 2), switch assemblies S2, S6, and S9 are turned onand switch assemblies S1, S3, S4, S5, S7 and S8 are turned off to form adischarging circuit 76 that includes the top plate of capacitor Cfb1connected to the hold capacitor 36, top plate of capacitor Cfb2connected to the bottom plate of capacitor Cfb1, and bottom plate ofcapacitor Cfb2 connected to ground.

In one embodiment, multiple “stages” of the switch capacitor circuits,as explained herein, are linked together, which may be used to gainadditional current output, with or without the need for the addition ofthe Hybrid power conversion/regulation circuits.

Referring to FIG. 7, in the illustrated embodiment, the switch capacitorvoltage divider circuit 32 also includes a control circuit 78 that iscoupled to each of the switch assemblies 72 to operate the switchcapacitor voltage divider circuit 32. The control circuit 78 includes avoltage sensing circuit 80 for sensing a voltage level of the rectifiedDC power signal being received from the rectifier circuit 30 and a gaincontroller 82 that is configured to select a gain setting of the switchcapacitor voltage divider circuit 32 as a function of the sensed voltagelevel and operate each of the plurality of switch assemblies as afunction of the selected gain setting. By providing a control circuit 78that selects the gain setting of the switch capacitor voltage dividercircuit 32 as a function of the sensed input voltage level, the switchcapacitor voltage divider circuit 32 is able to adjust the operation ofthe switch capacitor voltage divider circuit 32 to account forvariations of AC voltage levels in different countries and/or powergrids and deliver the intermediate DC output signal at a predefinedvoltage level and maintain optimum power efficiency. In the illustratedembodiment, the control circuit 78 includes a resistor divider 84, apair of comparators 86, a logic decoder 88, and a gain controller 82.The negative input of the comparators 86 is connected to a bandgapgenerator and the positive inputs are connected to the rectifier circuit30 line voltage, Vline.

Referring to FIGS. 4-6, in the illustrated embodiment, one or moreswitch assemblies includes an N-channel MOSFET switch 90, and a levelshifter 92 that is connected to the N-channel MOSFET switch 90 fordelivering a control signal to the N-channel MOSFET switch 90 tofacilitate operating the N-channel MOSFET 90. In addition, one or moreswitch assemblies 72 include a charge pump 94 that is connected to thelevel shifter 92 to provide a high-voltage signal required to close theN-channel gate during operation. In one embodiment, the charge pump mayinclude a Dickson charge pump. Alternatively, the charge pump 94 mayinclude any suitable charge pump that enables the power circuit 22 tooperate as described herein. In the illustrated embodiment, the chargepump 94 is configured to generate an output power signal having avoltage level that is greater than a switch assembly source voltage toenable the level shifter 92 to operate the N-channel MOSFET switch 90.In one embodiment, each of the switch assemblies 72 includes anN-channel MOSFET 90, a level shifter 92 coupled to the N-channel MOSFET90, and a charge pump 94 coupled to the level shifter 92. In anotherembodiment, two of more level shifters 92 may be connected to a singlecharge pump 94. Wherever in this specification the term NMOS is used, itcould be substituted with a PMOS and vice versa.

In the illustrated embodiment, at least one switch assembly 72 includesa level shifter 92 that is connected to an N-channel MOSFET switch 90.In addition, a charge pump 94 is connected to the level shifter 92 toprovide a power signal sufficient to close the gate of the N-channelMOSFET switch 90. In the illustrated embodiment, the charge pump 94 isconnected to the source voltage, Vsource, of the N-channel MOSFET and isconfigured to deliver an output signal to the level shifter 92 that hasa voltage level that is greater than the voltage level of the sourcevoltage, Vsource in the case of using an NMOS. In one embodiment, thecharge pump 94 is configured to deliver an output power signal, V_(DCP),having a voltage level that is approximately 15-20 volts greater thanthe source voltage, Vsource in order to assure proper gate operation.The gain controller 82 is connected to the level shifter 92 forproviding a low voltage control signal to the level shifter 92. Thelevel shifter 92 is connected to the source voltage, Vsource, and to thecharge pump 94, and is configured to deliver the control signal to theN-channel MOSFET 90 having a voltage level sufficient to operate theswitch assembly 72 as a function of the received control signal.

FIG. 13 is a schematic diagram of the secondary power circuit 28including a forward converter circuit 96. In the illustrated embodiment,the forward converter circuit 96 includes a primary voltage reductioncircuit 98 and a secondary voltage reduction circuit 100. The primaryvoltage reduction circuit 98 is configured to receive the intermediateDC power signal from the primary power circuit 26 and deliver asecondary DC power signal to the secondary voltage reduction circuit100. The secondary DC power signal has a voltage level that is less thanthe voltage level of the intermediate DC power signal. The secondaryvoltage reduction circuit 100 is configured to receive the secondary DCpower signal and generate the output DC power signal being delivered tothe electronic device 20.

In the illustrated embodiment, the primary voltage reduction circuit 98includes a transformer 102. The primary side of the transformer 102 isconnected to the primary power circuit 26 and the secondary side of thetransformer 102 is connected to the secondary voltage reduction circuit100. In one embodiment, the primary voltage reduction circuit 98 mayinclude a switch assembly 104 including a FET that is coupled to thetransformer primary side, and a control circuit 103 that is coupled tothe switch assembly 104 for selectively operating the switch assembly104 to adjust a voltage level of the secondary DC power signal. Thetransformer control circuit 103 may include a primary side voltagesensing circuit 105 for sensing voltage and current level of the DCoutput signal and operate the transformer switch assembly 104 tomaintain the voltage level of the DC output signal at a predefinedoutput voltage level and required current level. In this fashion atleast five parts are removed from the equation, which are normallyneeded with a secondary side sense controller, including anopto-coupler, opamp, an inductor, diode and a capacitor. In theillustrated embodiment, the secondary voltage reduction circuit 100includes a pair of diodes, an inductor, and a capacitor. In oneembodiment, the secondary voltage reduction circuit 100 may include adiode and a MOSFET (shown in FIG. 72). In another embodiment, thesecondary voltage reduction circuit 100 may include a pair of MOSFETs(shown in FIG. 50). The forward converter 96 may also include aresistor, capacitor, diode (RCD) circuit 150 (shown in FIG. 37). The RCDcircuit 150 is configured to perform a transformer reset when theprimary side switch 104 is off to avoid saturating the transformer 102.The forward converter 96 is a pulsed based step down converter. A dutycycle modulated digital pulse is applied to the primary side switch 104to convert the incoming DC voltage to an AC voltage. The transformerwinding ratio provides the step down. In this case, the step down isfrom 11:1. The secondary side sees an ac voltage on its terminals. ThisAC voltage is rectified by the secondary voltage reduction circuit 100diodes and filtered by the LC filter to produce a stepped down DCvoltage on the output. The duty cycle is modulated by either an analogor a digital servo loop. This servo loop looks at the dc voltage on theoutput side, compares it with a response to produce an error signal.This error signal is used to drive a comparator which converts thiserror in a pulse width modulated DC pulse. This DC pulse when applied tothe primary side switch gate 104 corrects the error on the output andmaintains regulation for various load levels.

In one embodiment, the transformer control circuit 103 may include aprimary side current sense circuit 107 that is connected to the primaryside of the transformer 102 to sense the load current and the loadvoltage to facilitate regulating the DC output signal to within 5% of apredefined load voltage. The control circuit 103 uses a current senseresistor 109 and measures across the primary winding. In the illustratedembodiment, the transformer control circuit 103 includes a comparator111 that drives the FET 104. In one embodiment, the resistor 109 is a0.10 ohm resistor. The control circuit 103 is configured to sense theload current on a pulse by pulse basis and sense the peak current. Forexample, in one embodiment, the control circuit 103 senses the voltageacross the resistor 109 and provides the sense current in a voltageformat when the switch 104 is on. When the switch 104 is off, thecontrol circuit 103 senses the differential voltage across the primaryside of the transformer 102. This differential voltage is the ΔV voltageacross the winding which may be approximately equal to Vprimary minusthe voltage at the drain of the off transistor 104. These voltages arescaled down to less than 5V for sensing by the control circuit 103. Boththe voltage and current of the primary winding are then sampled using aswitched-capacitor sample and hold circuit. The sample and hold circuitdrives the comparator 111. The other input of the comparator 111 is asample and held peak current voltage that we sense across the 0.1 ohmresistor 109. The inputs into the comparator 111 are scaled and gainedup and offset so that the inputs are under steady state, and thecomparator 111 drives a set-reset flow clock. The FET 104 includes anAND-gate that is driven by the comparator 111. A clock off thecomparator 111 adjusts the duty cycle of the AND-gate. The AND-gate alsohas a high duty cycle driven by a high pulse width clock, which is asawtooth signal. The other input of the AND-gate is the output of thecomparator 111 so then the comparator 111 modulates that duty cycle tosmall duty cycle or to a large duty cycle. In one embodiment, the clockis the 100 KHz clock for the forward converter servo loop.

A tertiary winding from the transformer is not needed as a supply forthe sensor. The supply is available from the primary side because thesensing circuit is on the primary side and supply is not needed from thesecondary side. The voltage across the primary side inductor and thecurrent that is going to the primary side FET 104 is used to determinethe output voltage of the system. In one embodiment, the FET 104includes a 200 volt Philips part device having a 2-volt threshold, whichmay use a 5 v signal to drive the FET 104 to turn it on without levelshifting. In another embodiment, a 10 volt LDO or 20 volt LDO may beused with a level shifter to go from 5 volts to 10 volts, or 5 volts to20 volts to operate the FET 104.

In the illustrated embodiment, the control circuit 103 uses the senseresistor 109 that is in the drain path of the MOSFET 104 to implement agated approach in which a sample and hold circuit obtains the peakvoltage right when the switch 104 is on between each square wave in thePWM cycle. The gating arrangement samples when the switch is on, becausewhen the switch is off there is no information available at that time.

In the illustrated embodiment, the power circuit 22 is configured toaccommodate different transformers having different turn ratios togenerate a DC output signal having various current and/or voltagerequirements.

In one embodiment, the power circuit 22 may not include the full wavebridge 38, rectifier circuit 30, and input capacitor, 40, such thatV_(LINE) is DC and thus the circuit can receive a direct current (DC) ifthe use case requires, and then conduct the voltage break down asfurther explained herein using the regulated buck circuit 34 and switchcap VB 32 are still used. However, in some use cases, especially withlow DC to DC voltage breakdown, the buck regulator 34 would not beneeded, and only the switch cap VB 32 would be used, whether one stage(as shown in FIGS. 2-12) only would be used. In this case, one couldeliminate the control signal 105 from the output, and rely solely on thecurrent sense resistor 109 and still maintain a tightly regulatedvoltage.

In another embodiment, for DC input variation of the circuit, the usecase may not require a transformer (if the transformer is not needed forthe voltage/current conversion, or if isolation is not needed) like inthe case of an internal part, such as is found in smart phones. In thisinstance, the transformer is not necessary and may be removed from thecircuit together with the FET that drives the transformer. In this casethe entire forward convertor controller circuit 96, 28 can be removed,and the C_(hold) capacitor 36 would be replaced with the sense resistorcircuit segment 109. Further, if an AC circuit does not need to berectified or isolated, than this circuit can work with AC as well as DC.

FIGS. 15A and 15B are schematic diagrams of the power module 12including a power controller integrated circuit (Tronium PSSoC) 106 thatmay be used with the electrical power circuit 22. FIGS. 16, 17A, and 17Bare block diagrams of the Tronium PSSoC 106. In the illustratedembodiment, the power module 12 includes a printed circuit board 108 andthe Tronium PSSoC 106 that is formed within a packaged chip and iscoupled to the printed circuit board 108. At least a portion of theelectrical circuit 22 is included within the Tronium PSSoC 106. Inaddition, the digital control may be conducted by either amicroprocessor, external or embedded on the chip or a state machine. Inone embodiment, some or all of the electrical circuits and electricalcomponents included in the electrical circuit 22 are included within theTronium PSSoC 106. The Tronium PSSoC 106 may be configured for use intwo primary power module applications including an Autonomous PowerModule (shown in FIGS. 16 and 28) and a Universal Power Module (shown inFIGS. 17A, 17B, and 29). For example, as shown in FIG. 16, theAutonomous Power Module includes a Tronium PSSoC 106 that is configuredto operate in an autonomous mode of operation that is based upon ananalog feedback approach for reduced cost. The Universal Power Module,shown in FIGS. 17A and 17B, includes a Tronium PSSoC 106 that isconfigured to operate in a universal mode of operation and that utilizesa microprocessor (μP) controller to provide feedback for regulation ofthe final output voltage.

In the illustrated embodiment, the Tronium PSSoC 106 is configured tomeet predefined requirements for traceability, marking, solderability,and/or solvent resistance. The Tronium PSSoC 106 is marked to indicate adate code, plant identifier, and traceability/authenticity code. Theauthenticity code provides a means of identification and verification asa genuine part against “knock-offs”. All production packaged componentson a tape and reel include the same unique date code, plant identifier,and traceability/authenticity code. Lot segregation may exist in such away as to prevent the mixing of date codes within the same lot ofcomponents. Packaged parts shall be marked to indicate the part number,date code and traceability code. Terminals are configured to meet thesolderability requirements of IPC-J-STD-001 and IPC-J-STD-002 for thepackaged Tronium PSSoC. The packaged Tronium PSSoC and its markings areconfigured to meet the requirements of the MIL-STD-202 test method 215.

The Tronium PSSoC 106 is an advanced power controller integrated circuitdesigned to provide output voltage regulation with high-efficiency andhigh accuracy. The Tronium PSSoC 106 provides the user with amulti-purpose device which can be used in a large variety ofapplications and because of the “Dial-a-Voltage” feature, the same chipcan be configured to work in practically any electronic device.Likewise, programmable output voltages are possible with the TroniumPSSoC, with little or no loss of efficiency across a variety of currentload conditions.

In the illustrated embodiment, the Tronium PSSoC 106 uses the switchcapacitor circuit 32 and the switch-mode buck regulator 34 to maintainhigh-efficiency regardless of the load voltage or current. For example,when no current is being drawn by the load the electronic device 20, theTronium PSSoC 106 enters a low-current mode of operation to minimize thetraditional ‘vampire’ current required to stay awake. In the illustratedembodiment, the Tronium PSSoC 106 includes the single-stage switchcapacitor circuit 32, a PID regulator control block 110 (shown in FIG.20) for PWM control of the forward converter secondary transformer 102,a switch-mode buck regulator controller 112, a buck regulator switchdriver 114, a current and temperature sense blocks 116, 12-bitAnalog-to-Digital Converter (ADC) 118 for voltage and currentmonitoring, a 10-bit Digital-to-Analog Converter (DAC) 120 (shown inFIGS. 17A and 17B) for feedback control, a digital control block 122 forcurrent monitoring state machine, serial input for opto-isolatorcommunications interface, a I2C serial interface port, and power managerunit 124 for on-chip voltage and current generation. Other types ofsensors, such as, sound, photo-detection, radiation and shock can alsobe added depending on the use case.

FIG. 18 is a block diagram of the Power Management Unit 124. In theillustrated embodiment, the power management unit (PMU) circuit block124 generates and supervises the bias voltages and currents required forproper operation of the Tronium PSSoC. Two linear voltage regulatorsprovide regulated 5.0V supplies for the low-voltage circuits of the IC,as well for external support devices such as the opto-isolators and anoptional external microprocessor. In addition to providing properinitialization of the IC upon connection to the line voltage, the PMU124 monitors the voltage supplies for fault conditions and provides amaster power-on-reset (POR) 126. In the illustrated embodiment, the PMU124 includes the bandgap voltage reference, current reference generator,a line-side low-power linear voltage regulator, a transformerprimary-side linear voltage regulator, and power-on-reset. To reducepower dissipation, the line-side circuits are powered from the LINE_0P1pin which supplies a voltage of approximately one-tenth of the LINE_INvoltage (Vline). This voltage is generated internally using an externalresistor divider connected to the LINE_IN and LINE_RDIV pins of the IC.Initialization of the PMU 124 begins with the application of therectified voltage at the LINE_IN pin.

The PMU 124 contains a low-power bandgap reference voltage and currentgenerator for the Tronium PSSoC 106 which is powered from the linevoltage. A high-precision temperature-compensated output voltage isprovided for use as a reference by subsequent circuit blocks, along withmultiple bandgap Proportional To Absolute Temperature (PTAT) currentoutputs. The bandgap output voltage can be trimmed at wafer probe tooptimize the temperature coefficient with the bg_trim[7:0] register bitsand stored in a one-time programmable (OTP) memory stored in amicroprocessor. The bandgap cell is self-starting, requiring only thedefault trim value for initialization. The bandgap cell is not disabledduring sleep mode, but is always powered on, and is designed forultra-low power operation.

The PMU 124 also includes a low-power linear voltage regulator (LPREG)that is provided to convert the high-voltage present at the LINE_INinput of the PSSoC to a regulated voltage for the low-power voltagedomain. The LPREG uses the bandgap reference voltage to generate aregulated output of 5.0V to drive the low power on-chip circuit blocksthat are always powered on including the Low-Frequency Oscillator forthe switch capacitor circuit 32, on-chip logic, etc. An external(off-chip) bypass capacitor may be used for noise filtering, connectedto the LPREG pin. The regulator is not disabled during sleep mode, butis always powered on.

The PMU 124 may also include a primary-side low voltage regulator thatis provided to supply the higher current requirements of off-chipopto-isolators, PWM gate drivers and other support circuits. An external10 μF bypass capacitor may be used for noise filtering, connected to theVREG5 pin. The voltage regulator may be disabled for test purposes withthe use of the en_Xv signal. When the en_Xv input to the cell is ‘low’,all of the internal analog currents in the cell are disabled and theoutputs are high impedance.

The POR 126 block monitors the internal supply voltage of the TroniumPSSoC as generated by the LPREG circuit block. For example, FIG. 19illustrates POR threshold voltages that may be used with the POR 126. Inone embodiment, for voltages at the LPREG pin less than the V_(POR)threshold voltage, the POR output will be asserted ‘high’ indicating areset condition. In addition, for voltages at the LPREG pin greater thanthe V_(POR) threshold voltage, the POR output will be de-asserted ‘low’for normal operation. Hysteresis is provided such that a reduction inthe threshold voltage occurs once the V_(POR) threshold is exceeded. Thethreshold derived from hysteresis is then equal to V_(POR)−V_(HYS). Aninverted version of the POR signal may also provided at POR_B.

In the illustrated embodiment, the switch capacitor voltage breakdowncircuit (SCVBC) 32 (i.e., the switch capacitor voltage divider circuit)included in the Tronium PSSoC 106 is configured as a voltage dividerthrough Capacitive Voltage Break Down techniques (CVBD). Throughcapacitors, it divides the rectified DC voltage present at the LINE_INpin to a reduced voltage at the CP2_OUT pin for use by the externaltransformer 102 and secondary voltage control loop. The externaltransformer 102 then further reduces this voltage to the desiredapplication voltage as a function of the primary-to-secondary windingsratio. In one embodiment, the SCVBC 32 is configured as a cascade of twoidentical stages, as shown in FIG. 17A. In another embodiment the SCVBC32 includes multiple switch capacitor stages, as shown in FIGS. 38-39.The SCVBC 32 is configured to deliver up to 50 mA per Capacitive BreakDown block, which consists of Switch Capacitor blocks which provide thevoltage breakdown by half or other divisionals. This provides andmaintains ≧95% efficiency across the range of load currents from 50 mAto less than 1 mA under light load conditions on the primary side of thetransformer 102. For example, assuming a ≧97% efficiency for theexternal transformer & rectifier, and overall module efficiency of≧92-97% has been simulated and is achievable. In one embodiment, theSCVBC 32 may include on-chip fly-back capacitors to maximize powerefficiency, external 2.2 μF bucket capacitors and two external 7.5 μFhold capacitors to minimize the voltage ripple. These capacitors areconnected to the CP1_OUT and CP2_OUT pins, respectively, for the outputsof the 1st and 2nd stages of the switch capacitor circuit. Both stagesare clocked at a rate of 1 KHz from a two-phase non-overlapping clockgenerator which is derived from an on-chip Oscillator.

Referring to FIGS. 17A and 17B, in one embodiment, for the Tronium PSSoC106, the SCVBC 32 output voltage at CP2_OUT is programmable over therange of 120-90 Volts in steps of 0.117 Volts with the use of an 8-bitbinary-weighted digital-to-analog converter. The SCVBC output is limitedto this range to ensure that the forward converter transformer 102provides most of the output current in the step-down process. The SCVBCis limited to an output current of 50 mA. If additional current isrequired for the application, the switch-mode buck regulator 34 may beenabled to provide up to 430 mA of current. Each stage of the SCVBC 32may be programmed to produce a voltage conversion ratio. Thisprogramming is done automatically in the Course Gain Control where therectified LINE_IN voltage is compared to the 8-bit DAC setting. Thedigital control of this DAC enables multiple voltages to be programmedto obtain the desired final output voltage required for the targetapplication. An example of the load voltages which can be programmedwith the DAC as a function of the transformer turns ratio.

Referring to FIG. 16, in one embodiment, the SCVBC 32 may include asingle-stage switch capacitor circuit with a corresponding divider ratioof 1, 0.66 or 0.5. The output voltage present is then reduced by theexternal (off-chip) forward converter 96 to obtain the final applicationoutput voltage of 5.0V. All analog and digital signals for the SCVBC(and Buck Controller) are generated in the 5V domain. The SCVBC ErrorVoltage is scaled to be within the XV domain using a resistor divider.The LINE_IN voltage is also scaled so that processing can be done withinthe XV voltage domain.

In one embodiment, shown in FIG. 16, the SCVBC 32 includes a GainControl block that uses the scaled LINE_IN voltage to determine theappropriate divider ratio for the SCVBC 32. The scaled LINE_IN voltageis compared to the Bandgap reference voltage to select one of three ormore possible divider ratios as a function of the AC Mains voltage.Final regulation of the output voltage may performed in the switchcapacitor regulator where the clock is turned on and off to control theamount of charge delivered to the hold capacitor.

Referring to FIGS. 17A and 17B, in one embodiment, the SCVBC GainControl block may use the scaled LINE_IN voltage and Output Voltage DACsetting to determine the appropriate Course Divider ratio derived fromthe combined divider steps in CP1 and CP2. In this way, settings for the120 and 90 Volt outputs as a function of world-wide AC input voltagescan be achieved. Final regulation of the CP2 output voltage is performedin the switch capacitor regulator where the clock is turned on and offto control the amount of charge delivered to the CP1 and CP2 holdcapacitors. The lowest divider ratio required for CP1 and CP2 should beprogrammed for the CP1 stage to minimize the voltage drop across thehigh-voltage NMOS switches.

The CP2 output feeds the primary winding of the Forward Regulator. Thefinal output voltage of the system is set by the following equation:(V _(SET) /XFMR _(RATIO))*dc=V _(OUT)

Where dc is the duty cycle for the Forward Regulator and should bemaintained at 0.5 or less to ensure the system transformer does notsaturate.

The SCVBC 32 includes a Dickson charge pump (DCP) 94 (shown in FIGS. 5and 6) that may be used to provide a boosted voltage for the gates ofthe NMOS high-voltage switches. The DCP's may be clocked at a clock rateof 1.6 MHz and generate gate voltages equal to the voltage at theLINE_IN pin plus approximately 18V. In addition, each NMOS high-voltageswitch 90 may include a corresponding level shifter to translate thedrive signal from the low-voltage domain to the boosted voltage providedby the DCP's. In one embodiment, this requires dual level shifters,other requirements may only need one level shifter. The input to thelevel-shifter is 5V and is translated to the 20V domain for use by theSCVBC 32. This same type of level shifter, scaled for output currentdrive, may be used throughout the Tronium PSSoC 106.

In one embodiment, as shown in FIGS. 17A and 17B, the Tronium PSSoC 106may include a Digital-to-Analog converter (DAC) that providesprogrammability for the output voltage of the switch capacitor circuit.An R2R current-mode DAC topology digitally scales the bandgap referencevoltage to the control voltage required by the switch capacitor circuitto maintain the output voltage programmed by the user. The outputvoltage range of the DAC is from 120-90V programmed in steps of 118 mVby the CP_DAC[7:0] register bits.

The SCVBC 32 may also include a switch capacitor regulator that includesa comparator and an AND gate that are used to control the charging ofthe SCVBC. In one embodiment, the comparator's inputs may include theOutput Voltage DAC and the scaled version of the CP2 output voltage. Forexample, if the scaled voltage from the CP2 output is greater than theDAC voltage, the comparator output is low and the 1 KHz CP clock isgated OFF. If the DAC Voltage is greater than the scaled CP2 outputvoltage, then the comparator output is asserted high and the AND gateenables the clock to charge up the output. In addition, the comparatormay be designed with hysteresis to minimize the CP2 output voltageripple. Moreover, the regulator may run both CP stages in thediscontinuous mode; that is, the clock pulses are only present whencharging of the 7.5 μF hold capacitors is required.

In the illustrated embodiment, if a stack of CVBD Modules are not used,then large current loads (up to 430 mA or more) are easily handled withthe use of a hybrid topology which includes a Switch-Mode Buck Regulator(SWR) 34 and the CVBD Module. The Tronium PSSoC 106 contains thecontroller for the SWR 34, which makes use of an external (off chip)PMOS switch (which can be an internal to the Chip PMOS or NMOS [withadditional Dickson Charge Pumps for gates]) to supply the high-currentdemands of the load. Since the high-current path is external to thePSSoC, the PSSoC is not required to dissipate the majority of the loadcurrent. This improves the overall system efficiency by eliminating thesource of additional parasitic losses in the PSSoC due to theON-resistance of the high-voltage devices. The SWR may be regulated atthe same frequency as the CVBD Module, or run at higher (500 KHz-1 MHz)to very high frequencies, while the CVBD Module is running at lowerfrequencies in order to remain more efficient. (The CVBD Module can berun at higher frequencies, but with current devices offered insemiconductor platforms today, this increases gate openings/closings,which increases losses).

In one embodiment, the buck regulator 34 may include the followingexternal (off chip) components: 1. Series High PMOS Switch. The PMOSSwitch may be selected for low RDS_(ON), low input capacitance and aV_(DS) of >400V; 2. High Voltage Buck Diode with High Volt Breakdown,extremely low leakage and switching current; and 3. Buck Energy StorageInductor. The inductor must have low ESR and be able to handleappropriate de-rated current. However, these parts, usually depending onthe frequency which runs the Buck (the higher the frequency the smallerthe value of the parts needed), may be internal devices/components onthe chip, and not external. With the application of GaN and/or GaA andDeep Trench Capacitor technologies, as well as technologies which puttransformers on the chip, all parts may exist on one chip.

The Tronium PSSoC 106 may also include a high-frequency oscillator thatis divided down to produce a 100 KHz (nominal) clock for use by the BuckRegulator PWM controller. The 100 KHz clock is dithered with a pseudorandom algorithm in the Digital Control block to ensure the suppressionof harmonics in the EMI spectrum. This clock is then Pulse WidthModulated to control the on/off time of the external Buck RegulatorPMOS/NMOS FET. The 100 kHz clock is converted to a saw-tooth ramp insidethe Tronium PSSoC 106 where it is compared to the Error Amplifieroutput. The Pulse Width Modulated signal from the Comparator output isthen applied to the level shifter input to control the on/off time ofthe external Buck Regulator PMOSFET. The Error Amplifier of the Buckregulator 34 receives feedback from the regulator by scaling the voltageat CP2_OUT with the use of a resistor divider. The voltage feedbacksignal is then conditioned using internal resistors and capacitors tocontrol the response of the Buck Regulator under all conditions. Theresulting transfer function for the regulation servo loop is comprisedof multiple poles and zeros to ensure that the regulator output isstable for the full range of load conditions from 50 mA to 430 mA. TheError Amplifier and PWM Controller for the Buck Regulator are alllocated in the 5 Volt domain with the final control signal being levelshifted to drive the external high-voltage PMOSFET switch.

The Tronium PSSoC 106 may also include a LDO Buck Regulator 128 that isused to create the high-side voltage necessary to drive the gate of thePMOS/NMOS FET for the Buck regulator 34. This voltage is then used tosupply the gate voltage required to drive the external PMOS/NMOS FET. Acapacitor is connected for filtering.

In the illustrated embodiment, the Tronium PSSoC 106 includes a CurrentSense Amplifier of the Tronium PSSoC senses the voltage across theexternal current sense resistor at pins RCSP and RCSN. This voltage issampled and held by a switched-capacitor difference amplifier anddigitized by the on-chip general-purpose ADC. The digital word is thencompared against programmed thresholds to enable or disable the BuckRegulator 34 as needed to optimize efficiency. The output of the CurrentSense Amplifier is also monitored for possible fault or alarm conditionssuch as over current, allowing a digital state machine that controls thecurrent sense feedback to disable the SCVBC 32 to prevent possibledamage.

The Tronium PSSoC 106 may also contain one or more oscillators whichprovide a 16 KHz frequency output and a 9.6 MHz frequency output. Theoscillators may share a common trim controller which allows thefrequencies to be trimmed using the osc_trim register bits.

The low-frequency (16 KHz) Oscillator is a line-side Oscillator thatruns continuously after the application of the line voltage at LINE_IN.It is supplied by the LPREG regulator. This oscillator output frequencyis divided down to a number, like 1 KHz to provide the clock for theSCVBC 32. The oscillator output, in that case, is also used as thereference clock for the Sleep mode Shut-down Timer. A high-frequency(9.6 MHz) Oscillator provides the master clock for the decoding of thesingle-wire serial data input. The oscillator 9.6 MHz output is dividedby 6 to provide the 1.6 MHz clock required by the Dickson Charge Pumpsin the switch capacitor circuit. It is further divided to provide theclock source for the Buck Regulator and Forward converter PWM ControlBlocks. These 100 KHz clocks are dithered with a pseudo random algorithmby the digital logic to ensure suppression of the harmonics in the EMIspectrum. The oscillator can be enabled with the osc_en register bit andis powered by the LPREG regulator on the line side.

In the illustrated embodiment, the Tronium PSSoC 106 includes anultra-low power ADC 118 to digitize a temperature sensor and currentsense amplifier analog voltages. These digitized voltages can then becompared by the Digital Control block to disable or restart the analogcircuitry. The ADC uses a successive-approximation (SAR) topology forlow-power and enhanced INL/DNL performance. The input to the ADC isprovided by a multiplexer. The multiplexer can select each of thechannels of interest for digitization by the ADC. The converted samplevalues are then stored in the ADC_SAMP register for use by the ControlState Machine. The ADC uses a low voltage supply and will be disabledwhen the device is in sleep mode.

FIG. 20 is a schematic illustration of a Proportional to Integral andDifferential (PID) Regulator Control circuit 110 that may be used withthe Tronium PSSoC 106. In the illustrated embodiment, the Tronium PSSoC106 includes a PID servo loop 130 to regulate the voltage at the outputof the forward converter 96 as load current is drawn from thesecondary-side of the external transformer. The PID block includes anError Amplifier, Saw-tooth Waveform Generator, Comparator and PWM ClockControl Block. The PID loop is designed to regulate the output voltageunder heavy fluctuation of load current without triggering anyinstability.

A PID Buffer Amplifier receives the feedback to close the Forwardregulation loop via the AUTO_ERR input. This is the output of theOpto-Isolator which provides a voltage to the PSSoC which represents theoutput voltage of the Forward converter. This voltage is then scaled onthe PSSoC with a resistor divider and buffered for the Error Amplifier.

The Error Amplifier for the Autonomous PID Loop is located on theTronium PSSoC with the compensation resistors and capacitors on-chip.The Error Amplifier uses the bandgap voltage as the reference for thePID Servo Loop. A Saw-tooth, or other, Waveform Generator provides aclock-based means of pulse-width-modulation (PWM) for the PID ServoLoop. The circuit receives the 100 KHz clock from the digital logic andconverts it to a saw-tooth waveform of the same frequency to be comparedto the output of the Error Amplifier. The outputs of the Error Amplifierand Saw-tooth Waveform Generator are compared by the PID Comparator togenerate the PWM clock required to drive the Forward converter. A DutyCycle Limiter is provided to ensure that the PWM output provided by thePID Comparator does not exceed 65%. This output is applied at the FWDOUTpin to drive the external transformer. In normal operation, the PWM dutycycle is limited to a range of 10-65% to avoid saturation of thetransformer.

In one embodiment, the PID Servo Loop is designed to operate at lowvoltage and deliver a maximum of the required DC current to the load.The regulation can be controlled up to a high percentage of absoluteaccuracy by using an LC filter on the secondary side and by properlysizing the internal R's and C's of the 3^(rd) order compensationnetwork. The LC filter double pole is given by the following equation:FLC=½π√L1C4.

The C1 capacitor has a certain ESR (series resistor) which produces azero. This zero generates a +90 degree phase shift: FESR=½πC1RESR.

The compensation loop has a certain bandwidth (Fc) which isapproximately 1/10th of the clock rate of the forward converter. Thegoal of the network is to maintain at least 45 degrees of phase marginat Fc: Phase Margin=180 degrees+Phase of loop.

The PID loop has 2 zeroes and 2 poles. The 2 zeroes are necessary toprovide 180 degree of phase boost in order to negate the 180 degree ofphase loss due to the output LC filter. Both zeroes are placed at about˜50% of the LC filter pole frequency. Two poles are then located at theswitching frequency of the converter (100 KHz). This allows us tocalculate C1, C2, C3, R2 and R3. R1 is set to a reasonable value inorder to start the calculation procedure.

In another embodiment, the PID Servo Loop is designed to operate formultiple output voltages which can be programmed by the user for therequired application. The loop may deliver ny current, but in thisillustrated case 4.5 A of DC current to the load with a regulation of upto 0.1% of absolute accuracy. Feedback for the Universal loop isprovided by the external microprocessor and voltage sense supportcircuits, and is input to the Tronium pin as a serial data stream. Aparallel-to-serial conversion is then performed on the digital wordwhich is converted to an analog voltage for application to the erroramplifier as shown in FIG. 20. Conversion to analog is performed with anon-chip DAC which is updated at the frequency of the incoming data rate.The reference voltage for the PID error amplifier is generated by asecond DAC which is programmed by the microprocessor.

A Digital-to-Analog converter (DAC) generates the analog referencevoltage for the PID Control Loop based upon the digital programmed inputfrom the microprocessor. The Digital-to-Analog converter (DAC) as shownis a 10-bit scheme, but can be any number of bits. The DAC may alsoprovide feedback for the PID Control Loop by converting the digital wordreceived from the pin to an analog voltage for input to the loop. TheDAC voltage is input to the error amplifier and compared to the analogreference voltage to produce the error voltage for the control loop. TheDAC provides updates to the loop at the rate of the incoming data.

Referring to FIGS. 17A and 17B, in one embodiment, the Tronium PSSoC 106may include an on-chip ΔV based temperature sensor that enables the ICto sense the temperature of the die or module. In this example, ageneral purpose 12-bit ADC is used to digitize the differential voltage.The digitized value is then compared to programmable thresholds in orderto shut down or re-enable the Tronium PSSoC depending on temperatureconcerns.

In the illustrated embodiment, the Tronium PSSoC 106 provides two modesof operation and four wake-up states (W0-W3) applied upon powerup.

Startup Mode. During Startup Mode, the Tronium PSSoC controls thestartup behavior of the module when power is first applied or when aphone is plugged in (in the case of a charger). When power is firstconnected to the AC Mains, the rectified and filtered LINE voltagepresent at the LINE_IN pin of the IC increases until it reaches itsfinal DC value. The basic support circuits of the Tronium PSSoC areconsequently powered up to initiate the power management functions. Atiming diagram of an exemplary startup sequence of events is shown inFIG. 24, beginning with the application of the LINE_IN voltage at t=0.

The line side has three circuit blocks that are always powered ON: 1.Low-Power Bandgap Reference; 2. Low-Power 5V Regulator (LPREG); and 3.Low-Frequency Oscillator. Other circuits may be powered, but in thisexample it has been reduced to three in this instance in order to drawextremely low stand-by power. These circuits draw power directly fromthe LINE_IN input with no transformer action to increase the availablecurrent. As a result, they are designed for ultra-low power consumption.Alternatively, the transformer could be enabled, but this would reduceefficiency.

Normal Mode. Following the application of power and the completion ofthe wake-up states, the Tronium PSSoC 106 will enter the Normal Mode ofoperation. The Normal Mode of operation is maintained until thevoltage/current becomes extinct or passes a low current threshold wheretypically the microchip inside the battery system begins resisting thecurrent to prevent overload. In the normal mode of operation, theTronium PSSoC exits the Sleep Mode as a result of the detection of loadcurrent. Regulation of the load occurs as the Buck Regulator and SCVBCsupply the necessary current. In this mode of operation all Troniumcircuits are powered ON and responding to the external stimulus.

In one embodiment, combining the elements of Normal Mode, Start Up Modeand Sleep Mode the battery can be provided a “bump” charge. In thisinstance another mode, called Bump Charge Mode would be executed when itis determined by the logic in the chip that a full charge has beenexecuted, meaning a drain from a higher current to lower current over agiven period of time. This Bump Charge mode of operation can exist inthe state machine or be enabled/disabled via the I2C interface and wouldinstruct the circuit to “disconnect” several times and begin rechargingup to a maximum threshold of approximately 150 milliamps with aninterval in between. In this fashion, the battery would be prompted toreceive an additional trickle charge to ensure that it is really full,not just stating “full” on the device battery indicator. This will solvethe problem where cell phones only charge to about 80-90% of theirbatteries capacities, thus, over time, while the indicator stillregisters the battery at 100%, it is really a 100% of 80% of thebattery's capacity, not 100% of 100% of the battery's capacity. Underthe Bump Charge Mode, the Tronium PSSoC digital provides an additionalcurrent threshold which is higher than the sleep threshold so that theSleep Mode function, set out below, is not compromised.

Sleep Mode. The Tronium PSSoC must use minimal power when connected tothe AC Mains power and no charging or power supply function is required.This requires the electrical circuit 22 to have at least two distinctpower domains: 1) the line side domain and 2) the primary side domain.The line input side is the domain that must be capable of being poweredat all times. There is also a 1.6 MHz Oscillator that is used for theDickson Charge pumps. This oscillator remains OFF in the SLEEP mode. The16 KHz oscillator is used as a countdown timer to wake the Tronium PSSoCwhen the programmed countdown time has been reached.

In the illustrated embodiment, the Tronium PSSoC 106 includes a DigitalControl block 122 that provides the user the ability to manage numerousaspects of the Tronium application in setup, programmable, normal, test,or evaluation modes of operation. A microprocessor or state machines areprovided to monitor the output voltage and current of the Switchcapacitor circuit and include configurable registers which providefeature selection and programmability for both the normal mode ofoperation and the low-current or ‘sleep’ operating mode. Communicationinterfaces are also provided for external devices as required by theapplication.

FIG. 21 is a block diagram of a Tronium universal digital control block132 that may be used with the Tronium PSSoC 106. FIG. 22 is a blockdiagram of a Tronium autonomous digital control block 134 that may beused with the Tronium PSSoC 106. FIG. 23 is a flow chart illustrating amethod of operating the power circuit 22. FIG. 24 is a graphicillustration of a state transitions that may be implemented by theTronium PSSoC 106.

Referring to FIG. 21, in one embodiment, the Tronium PSSoC 106 includesthe universal digital control block 132. The Tronium universal digitalcontrol block 132 provides the following functions for control of theUniversal Module: Control State Machine, Clock Generator, ADCController, Clock Dither LSFR, I2C Interface—Mono or Dual CommunicationMode, Programmable Communication Mode, microprocessor Interface,Test/Eval Multiplexer, and/or Register File.

The Control State Machine or microprocessor/microcontroller determinesthe proper operating mode of the Tronium Module by monitoring the outputcurrent of the switch capacitor circuit. At least two modes of operationare provided including a Sleep mode and a Normal regulation mode. TheControl State Machine or microprocessor also provides four states towake-up the PSSoC, plus the Bump Charge Mode, upon the first applicationof power, or when exiting from the Sleep mode. In addition, the statemachine or microprocessor continually monitors the output voltagecurrent for an over-or-under-current alarm condition.

Monitoring of the switch capacitor output current is achieved in theanalog subsystem or in the microprocessor with the use of a CurrentSense Amplifier and an Analog-to-Digital Converter (ADC). The DigitalControl block provides control of the ADC and can perform periodic gainand offset correction for the ADC. The ADC samples are then compared tothe programmed digital thresholds for switch capacitor current requiredby the Control State Machine.

A Clock Generator provides the clocks required for the analog anddigital subsystems, and also enables clock gating to minimize powerconsumption in the Sleep mode of operation.

The Digital Control block provides a single-wire serial interface tosupport configurability of the PSSoC via an external microprocessor; ora multi-wire interface which will support two way communication betweenthe Tronium PSSoC and the microprocessor or state machine. A ClockDither Linear Feedback Shift Register (LSFR) is included to generatepseudo-random numbers for dithering of the Forward and Buck RegulatorPWM clocks. The pseudo-random number is used by the analog subsystem todither the high-frequency oscillator output. An I2C port is included formanufacturing settings, test, evaluation, updates, health-checks anddebug. The Register File which contains configuration registers fordevice operation can be accessed using the I2C interface. A digitalmultiplexer is provided to selectively multiplex various internaldigital signals to the DIGTST output pin for test purposes.

Referring to FIG. 22, in one embodiment, the Tronium PSSoC includes theautonomous digital control block 134 that provides the followingfunctions for control of the Autonomous Module: the Control StateMachine or microcontroller; Clock Generator; ADC Controller; ClockDither LSFR; I2C Interface; Test Multiplexer; and Register File. TheControl State Machine determines the proper operating mode of theTronium PSSoC 106 by monitoring the output current of the switchcapacitor circuit at the CP_OUT pin. Two modes of operation are providedincluding a Sleep mode and a Normal regulation mode. The Control StateMachine or microcontroller also provides four states to wake-up the ICupon the first application of power, or when exiting from the Sleepmode. In addition, the state machine monitors the output current for anover-under-current alarm condition and Bump Charge Mode.

Monitoring of the switch capacitor output current is achieved in theanalog subsystem with the use of a Current Sense Amplifier and an 12-bitAnalog-to-Digital Converter (ADC) is used in this example. The DigitalControl block provides control of the ADC and can perform periodic gainand offset correction for the ADC. The ADC samples are then compared tothe programmed digital thresholds for switch capacitor current requiredby the Control State Machine and/or microcontroller.

A Clock Generator provides the clocks required for the analog anddigital subsystems, and also enables clock gating to minimize powerconsumption in the Sleep mode of operation or Bump Charge Mode.

A Clock Dither Linear Feedback Shift Register (LSFR) is included togenerate pseudo-random numbers for dithering of the Forward and BuckRegulator PWM clocks. The pseudo-random number is used by the analogsubsystem to dither the high-frequency oscillator output.

An I2C port is included for manufacturing settings, evaluation,upgrades, resets, chip health-checks, test and debug. The Register Filewhich contains configuration registers for device operation can beaccessed using the I2C interface.

A digital multiplexer is provided to selectively multiplex variousinternal digital signals to the DIGTST output pin for test purposes.

In the illustrated embodiment, the Tronium autonomous digital controlblock 134 includes a State Machine to determine the proper mode ofoperation for the Autonomous Module based upon the load current.

As shown in FIGS. 23 and 24, the Control State Machine provides fourwake-up states (W0, W1, W2 and W3) and two operating modes; a NormalMode and a Sleep Mode.

Wake-Up 0 (W0)—When power is applied, the line-side circuits wake up:the bandgap (BG) and the low-power regulator (LPREG) power up. After theLPREG is stable, por_b is released and the system transitions to Wake-Up1 (W1).

Wake-Up 1 (W1)—The low-frequency oscillator (LF_OSC) and thegain_control (GAIN_CTRL) get enabled. At the same time, thehigh-frequency oscillator (HF_OSC) and the charge_pump (CP) get enabled.The CP is set to not regulate. When the LF_OSC is stable, the lf_clk tothe digital block is released at which point (a) the 10 mS counterstarts up and (b) the 1 kHz clock to the switch capacitor becomesactive. When the 10 ms counter expires, the system transitions toWake-Up 2 (W2).

Wake-Up 2 (W2)—The switch-regulator (SWR) gets enabled, the CP is set toregulate and the 1 mS counter starts. When the 1 mS counter expires, thesystem transitions to Wake-Up 3 (W3).

Wake-Up 3 (W3)—The forward PID gets enabled and two counters start up:the 20 mS counter and the 250 mS counter. The following scenariosprovoke transitions from this state: a.) The 20 mS counter expires andthe forward PID override option is on: The system transitions to normalmode (NM); b.) The 20 mS counter expires, the forward PID overrideoption is off and the forward PID stabilizes before the 250 mS counterexpires: The system transitions to normal mode (NM); c.) Sleep mode isnot disabled, the forward PID override option is off and when the 250 mScounter expires, the forward PID has not stabilized yet: The systemtransitions to sleep mode.

Normal Mode (NM)—The current sense block (CUR_SNS) and the ADC getenabled. If self-calibration is not disabled, the ADC uses the first twosamples for gain and offset calibration and signals that the ADC data isokay when the third sample is ready. If self-calibration is disabled,the ADC performs gain and offset correction with the values programmedin the designated registers and signals that the ADC data is okay whenthe third sample is ready. When the ADC data is okay, the systemmonitors the current load. The following mutually exclusive conditions,the thresholds for which are programmable, can occur: 1. Over-currentcondition: The system sets the over-current status bit. If sleep mode isnot disabled, the system transitions to sleep mode (SM); and 2.Under-load condition: If the LCSD_EN pin is high and sleep mode is notdisabled, the system transitions to sleep mode (SM); and 3. Low-loadcondition: The system shuts down the SWR when it detects a low-loadcondition and turns the SWR back when the low-load conditions subsides.

Sleep Mode (SM)—The system disables the HF_OSC, the CP, the SWR, theforward PID, the CUR_SNS) and the ADC. It also starts the sleep counter,the duration of which is programmable. The default sleep time isapproximately 5 seconds, which may be adjusted depending on useapplication. The system stays in sleep mode if the forward PIDpreviously hadn't stabilized on entry to sleep mode. In this case, thesystem can be restarted in W1 by triggering the EXT_RST pin or in W0 byremoving power. If the forward PID was okay on entry to sleep mode, thesystem transitions to the W1 state when the sleep counter expires.

In the illustrated embodiment, the transition between the Normal andSleep modes of operation is achieved by monitoring the output current ofthe switch capacitor circuit via the Current Sense Amplifier and theADC. In addition, the Control State Machine can disable the SWR BuckRegulator if the load current decreases to the programmed digitalthreshold. Monitoring of the current and the corresponding modetransitions is illustrated in the diagram of FIG. 24.

Referring to FIGS. 21 and 22, the digital control block 122 may includea clock generator which generates all the clocks required by the digitalsubsystem. Three clock domains are provided which are asynchronous toeach other, a low-frequency clock domain, a high-frequency clock domain,and a I2C clock domain.

The Low-Frequency Oscillator in the analog subsystem provides a clock,in the illustrated example, a 16 kHz clock for the digital subsystem(lf_clk). In addition to the clock used by the Register File, the ClockGenerator derives the following clocks from lf_clk: 1. sys_clk—An 8 kHzclock with a 50% duty cycle which clocks the control state machine. 2.adc_gclk—A gated version of sys_clk which clocks the ADC controller.This clock is gated off in sleep mode. 3. lfdiv_clk—A divided clock witha programmable frequency of 1, 2 or 4 kHz with a 50% duty cycle to beused in the analog block. This clock is gated off in sleep mode.

The oscillator can be bypassed in the analog subsystem via the TSTMD0input to enable the application of a 16 kHz clock from the EXT_CLK pin.

The High-Frequency Oscillator in the analog subsystem provides a 1.6MHz, 50% duty-cycle clock which is further divided by the ClockGenerator to create the hfdiv_clk. The hfdiv_clk is programmable via theRegister File to provide frequencies of 100, 200, and 400 kHz. Thehfdiv_clk is also used in the digital for the Clock Dither LFSR and inthe analog for the Buck Regulator and Forward PID loops. The clock shutsoff in sleep mode when the HF Oscillator is disabled in the analog.

The I2C Interface uses the clock input at the SCLK pin to controloperation of the I2C port. Data rates of up to 100 Kbps are supported.

In the illustrated embodiment, the digital control block 122 alsoincludes an ADC controller which generates the control signals for thegeneral purpose 12-bit ADC in the analog subsystem. It also controlsselection of the input to the ADC for conversion via the ADC multiplexerand the ADC_MUX_SEL registers in the CONTROL0 register. The ADC outputformat is magnitude. The Digital Control block performs aself-calibration routine once when the ADC is first enabled. The DigitalControl block can configurably use the gain and offset correction valuescalculated during the self-calibration, or use the gain and offsetcorrection values written to the ADC_GAIN and ADC_OFFS registers.

During the self-calibration routine the offset and gain correctionvalues are determined as described below.

The Offset is determined first as follows: Set the ADC input mux toselect the Reflo reference voltage. Do one ADC conversion. The Idealvalue would be 0. Load the ADC Conversion data into the local ADC OffsetCorrection Register.

The Gain is determined next as follows: Set the ADC input mux to selectthe Refhi reference voltage. Do one ADC conversion. The Ideal valuewould be 4095. Load the local ADC Gain Correction register with theresults of (ADC Conversion data−Offset Correction)/4095.

Following the self-calibration phase, the ADC Conversion values arecorrected as follows: ADC Corrected data=(ADC Conversion data−OffsetCorrection)/4095.

The Clock Dither LFSR provides pseudo-random number values to implementdithering on the 1.6 MHz clock to mitigate EMI. The LFSR is a 12-bit,maximum-sequence, Galois-type LFSR with the polynomial of x12+x6+x4+x+1.The Clock Dither LFSR can be selectively enabled or disabled with thedith_en register bit in the Control register.

In one embodiment, the Tronium PSSoC digital control block 122 mayinclude a configurable down counter with a range of 0.512 Sec to 16.384Sec, to implement the Sleep Timer function. The Step size is 512 mS. Thecounter receives its clock from the Clock Generator block where it isdivided down from the LF Oscillator clock. The counter is loaded withthe sleep_time value programmed in the SLEEP_CTRL register. The counterwill count down from this value until it reaches zero at which time itnotifies the Control State Machine that the Sleep Timer has expired.

FIG. 25 is a schematic illustration of a communication interface thatmay be used with the Tronium PSSoC 106. FIG. 26 is a schematicillustration of a microprocessor communication protocol that may be usedwith the Tronium PSSoC 106. In the illustrated embodiment, thecommunication may be uni-directional or bi-directional. The TroniumPSSoC 106 contains one or more communication interfaces, here describedas three interfaces: 1) a microprocessor interface, 2) a single or dualcommunications/update interface for programming values or returninginformation to the state machine/micro, and 3) a test/eval interface.The microprocessor interface will be used to communicate with anexternal microprocessor for certain products, the communications/updateinterface may update the micro or any of the values internal in thechip. This allows for product configurability and for implementation ofa control loop for the Tronium charger. For the Tronium PSSoC, this canbe either a read/write or a write only interface, i.e., themicroprocessor will or will not be able to read from the PSSoC dependingon the type of communication determined: one way or multilateral.

The test/eval interface will be used in the manufacturing testenvironment, and for bench evaluation of the Tronium PSSoC. It willallow for write and read access to the on-chip registers. The upgrade,eval, health-check and reset interface will be used to reprogram a chip,change its voltage/current output, or change other reprogrammableportions of the control logic, including thresholds, as well as runscans to help determine if anything is wrong with the chip(health-check).

Typically, only one interface can be selected at a time, but this can bechanged based on the state machine or micro settings. The IF_SEL inputpin selects the I2C when ‘1’ and the microprocessor interface when ‘0’.

Microprocessor Communication Interface. The Tronium PSSoC may alsoprovide a single-wire serial interface to support configurability of thePSSoC. The interface consists of uni- or multi-directional datainput/output. The protocol is shown in FIG. 26. All packets will behomogenous in structure and length unless otherwise necessary. Eachpacket will be a certain number of bits. The packet fields are describedbelow. By adding another wire, a dual communication interface may be hadso that the information is multi-directional.

To support reliable communication, the data may be Manchester Encodedper the IEEE 802.3 Communication Standard. The receiver will then use anover-sampling clock to maintain bit synchronization over the packet. Thebit rate will be 600 Kbps. The incoming data will be oversampled by afactor of 16 times the bit rate. The oversampling clock is therefore 9.6MHz, and is sourced from an on-chip Oscillator.

Start: A single bit whose value is the non-idle state of the signalline. This will be ‘1’ for this application. R/W: A single bit toindicate a read or write request. When ‘0’, the data is written to theselected Tronium register. Note that Tronium only supports writeaccesses. Addr[4:0]: 5 bits used to address the Tronium configurationregisters. Data[9:0]: 10 bits to be written to the selected Troniumregister. For cases where the target register is less than 10 bits, datawill be right justified. For example when writing to an eight bitregister, Data[7:0] will be written to the addressed register location.Idle: A single bit whose value is the idle state of the signal line.This will be ‘0’ for this application.

Data is transferred MSB first. For example, Addr[4] is transmitted firstin time by the host. The Tronium implementation will or will not supportread operations of the ASIC registers by the host depending on theprogramming. The R/W bit is included for future expansion.

FIG. 27 is a timing diagram of an Inter-Integrated Circuit (I²C) 136that may be included in the Tronium PSSoC 106, that allows for datatransfer between integrated circuits. In the illustrated embodiment, theTronium PSSoC 106 contains an I²C slave port to support testing of thedevice. The I²C address is configurable using the I2C_ADDR pins. TheI2C_ADDR inputs are compared to the I²C Slave Address bits. The TroniumI2C Bus protocol is shown FIG. 27. The I²C Interface supports bittransfer rates up to 100 Kbs. The I²C interface runs entirely off theI2C SCLK clock input.

I²C Write Operations: The Tronium PSSoC supports writes to the TroniumMemory Mapped registers over the I2C Slave port. After receiving an I2Cslave address which matches the Tronium I²C address, the next byte,shown as byte1 in FIG. 27, will contain the 5 bit address field for theTronium Register File addresses. The Tronium PSSoC only supports accessof one register per command.

I²C Read Operations: The Tronium PSSoC supports reads from the TroniumMemory Mapped registers over the I²C Slave port. The read operationrequires two I²C operations. First, an I²C write to the RDREQ registerwhere the data in byte2 is the Tronium Memory Map address of theregister to read. Then an I²C read command will read the requestedregister. The Tronium only supports accessing one register per command.

Note that there is a delay between the I²C Write operation and the timeat which the RDREQ register is updated. This means that following theI²C Write operation, the I2C Master must wait 400 μsec before issuingthe I²C Read operation. This wait time only applies to the first I²Cread following the I²C Write to update the RDREQ register.

In one embodiment of the Tronium PSSoC the digital memory hasintelligence where if the Tronium PSSoC is powering a television, if atelevision has not been used from a certain time period to another, suchas midnight to 7:00 o'clock A.M. for a fixed number of days, the Troniumwould always put itself into Sleep Mode during these times to conserveenergy and not re-engage in the current sensing routine of the wake-upsequencing.

In another embodiment of the invention, the Tronium PSSoC is connectedthrough its I²C interface to wireless (like BlueTooth®) or power-linetype communication protocols and devices, either external, on-chip oron-module, in order to receive instructions to the state machine ormicroprocessor. In this fashion there could be “real-time” instructionsgiven to the Tronium about when to go to Sleep Mode, when to wake up,and reset, upgrade or change other preconditions, like over-voltage orPWM regulation. In this fashion, the Tronium PSSoC can have “real-time”sensing and switching of its control mechanism to achieve differentlevels of frequency, speed, or adapt to low power situations, like insome countries, where the grid typically runs under-voltage duringsignificant portions of the time. In this case the Tronium PSSoC can getreal-time information about resets, operation, or shutdowns/restarts,including real-time commands from its owner, even from a cell phone ortablet through the use of cell system to inside the home communicationtechnologies. In this case a person may want to shut down power tocertain electronic equipment or electronic devices powered by theTronium PSSoC while away, and this could be accomplished through thecommunication interface over wireless or wire communication technologiesgiving specific instructions through the I²C interface in the TroniumPSSoC, instructing it to shut down the device, and even pre-setting thetime it should wake up.

In another embodiment of the invention, and when used as a charger orconstant supply power, the Tronium PSSoC is small enough to fit into awall plug attached to the cord, therefore eliminating the need for acharger “box” or laptop “brick”.

In one embodiment, the Tronium PSSoC 106 has several test structures tosupport manufacturing, programming, eval, upgrading, health-check,communication, test and bench evaluation. The Tronium PSSoC provides twotest registers for controllability and observability of key internalfunctions and control signals. The TEST_CTRL0 register provides the userwith the ability to selectively enable, disable, or override the controlof individual analog circuit functions in the Tronium PSSoC to providean alternate method of control should the Control State Machine need tobe bypassed. The TEST_CTRL1 register provides the ability to multiplexinternal analog and digital signals to the ANATST and DIGTST output pinsfor test purposes.

Many modifications and variations of the present invention are possiblein light of the above teachings. The invention may be practicedotherwise than as specifically described within the scope of theappended claim.

FIG. 30 is a connection diagram that may be used with the Tronium PSSoC106. FIGS. 31 and 32 are additional schematic illustrations of theTronium PSSoC 106. FIG. 33 is a flow chart of an algorithm for alow-current detection and an error detection that may be used with theTronium PSSoC 106. FIGS. 34 and 35 are schematic illustrations of thepower circuit 22 including the Tronium PSSoC 106. In the illustratedembodiment, the Tronium PSSoC 106 is an advanced power controllerintegrated circuit (IC). The Tronium PSSoC 106 and correspondingintegrated Module provide a low-cost, highly efficient means to convertthe AC line voltage present at a typical home or business electricaloutlet to a reduced regulated DC voltage for consumer electronicapplications. Typical applications include, but are not limited to,charging systems for cell-phones, tablets or other handheld devices, USBpower conversion, power supplies for consumer, medical and industrialdevices, and many other possible uses.

The Tronium PSSoC provides high efficiency, low noise, and low EMI withthe configurations and features as set out above. In addition, theAC-DC, DC-DC converter has high power density, low cost, and electricisolation. These advantages are achieved from integrating otherwisediscrete parts onto the chip, utilization of the Switch CapacitorsVoltage Breakdown scheme and primary side sense/control. Thus, the keyfeatures of the Tronium PSSoC are as follows: Support for wide range ofavailable AC or DC input voltages and frequencies; Programmable OutputVoltage and auto-detect of input voltage with automatic setting toconfigure to the input voltage for proper operation; High-Efficiencyswitch capacitor circuit for AC-DC, DC-DC Conversion; PID (or similar)Regulation Control Loop for High Accuracy; Digital State Machines forCurrent and Temperature Monitoring; Ultra-Low Power Dissipation for Idle(Vampire) Mode of Operation; Opto-Isolated Microprocessor Interface forConfiguration and Control; and Communications Port for ManufacturingTest.

The analog and digital interfaces, inputs, and outputs of the TroniumPSSoC are able to withstand Voltages and Currents that are outside ofthe typical operating range. The unit is also operable over a widetemperature range and provide ample ESD immunity.

The Tronium PSSoC provides inputs and outputs to interface to theoutside world and external circuitry. These include but are not limitedto: power inputs, power outputs, low current shutdown enable inputs,mode selection input, intermediary connections for which externalcircuitry is required, test connections, communications connections,power outputs, regulator outputs, connections for PID based PWM, FETdrive outputs, and feedback inputs.

The Tronium PSSoC is an advanced power controller integrated circuitdesigned to provide output voltage regulation with high-efficiency andhigh accuracy. The advanced features of the Tronium PSSoC provide theuser with a multi-purpose device which can be used in a large variety ofapplications. Programmable output voltages are possible with the TroniumPSSoC, with little or no loss of efficiency across a variety of currentload conditions.

The Tronium PSSoC uses a proprietary switch capacitor circuit system tomaintain high-efficiency regardless of the load voltage or current. Whenno current is being drawn by the load, the device will enter alow-current mode of operation to minimize the traditional ‘vampire’current required to stay awake as well as scale the number of activesubsystems to the load in order provide high efficiencies across a wideloading range.

A top-level block diagram of the Tronium PSSoC is shown below, and iscomprised of the following major circuit blocks: High-VoltageMulti-Stage/Multi-Branch switch capacitor voltage divider circuit; PID(or other switched mode control scheme), Regulator Control Block for PWMControl of Secondary Transformer; Current and Temperature Sense Blocks;ADC or Comparator for Voltage and Current Monitoring; DAC, PWM, or othersignal for Feedback Control; Digital Control Block for Voltage & CurrentMonitoring State Machines; Communications Interfaces; and PowerManagement for On-Chip Voltage and Current Generation and other powerrequirements. The blocks in the IC may also include internal circuitsfor rectification.

Power Management. The power management block provides necessary powerrails and references to the rest of the IC. It is comprised of voltageregulators, current references and voltage references. It also includesall necessary buffering and amplification needed for IC usage. The powermanagement system also contains a reset controller which manages theshut down and start up of the system on power cycle.

Switch Capacitor Voltage Breakdown Circuit. The switch capacitor voltagebreakdown circuit (i.e., the switch capacitor voltage divider circuit)of the Tronium PSSoC works as a near lossless voltage divider which iscontrolled by algorithms in the controller. According to whichalgorithms (for input and target output) are enabled, it divides therectified DC voltage present at the LINE_IN pin to a reduced voltage atthe CP2_OUT pin for use by the external transformer and secondaryvoltage control loop. An external transformer can then further reducethis voltage to the desired application voltage as a function of theprimary-to-secondary windings ratio, as well as provide isolation ifdesired.

The switch capacitor circuit is configured as a cascade of multipleidentical stages with multiple parallel branches as shown below. Theparallel branches are switched in or out of the circuit based upon theload current that is sensed by the current sense amplifier. This enablesthe switch capacitor circuit to maintain high efficiency across the widerange of load currents. In the diagram below, the number of parallelsubsystems is 4 comprising two stages. The number of parallel systemsand conversion stages may change so that the system is best optimizedfor a particular input/output voltage ratio or power requirement.

The switch capacitor circuit uses on-chip or off-chip fly-backcapacitors to maximize power efficiency and external hold capacitors tominimize the voltage ripple. These capacitors are connected to theCP1_OUT and CP2_OUT pins, respectively, for the outputs of the 1st and2nd stages of the switch capacitor circuit. All stages are clocked by anoscillator, or each stage may have its own dedicated oscillator. Eachbranch of the switch capacitor circuit may have an independent enable.These capacitors may be “deep trench” type monolithic capacitors insilicon or gallium. The transistors associated with the capacitors mayalso be either created in any type of silicon or gallium.

The output voltage is programmable over the range of voltages for agiven range of applications with high resolution with the use of adigital-to-analog converter (DAC). The digital control of this DACenables multiple voltages to be programmed at the CP2_OUT pin to obtainthe desired final output voltage required for the target application.

The switch capacitor circuit output settings of the other switchcapacitor circuit stages can be determined by the user or derived fromthe measured AC line Vin, so that an optimum ratio between Vin and Voutcan be realized.

Regulation of each switch capacitor circuit stage is obtained with theuse of an Operational Trans-conductance Amplifier (OTA). The OTAregulates the current applied to the fly-back capacitors in each stageas a function of the difference between the output voltage and the inputreference voltage. The input reference voltage may be programmed,derived, or fixed depending on application.

Voltage measurement of the incoming line may be taken in order tooptimize the switch capacitor circuit settings. This setting calculationcan be performed on-chip, off-chip, or on the fly through appropriate onchip circuitry, so that the outputs of each switch capacitor circuitstage are in the most optimized ratios.

Current Sense Amplifier. The current sense amplifier in the TroniumPSSoC allows the device to measure current as part of the feedback loopas well as error reporting. The current can be measured by an ADC orthrough a series of comparators with varying thresholds.

PID Control Loop. The Tronium PSSoC provides aProportional-to-Integral-and-Differential, PID, loop or alternative PWMcontrol circuit in order to drive the primary side of the isolationtransformer, a buck, a boost, or a buck-boost circuit. This circuit isto provide post regulation and isolation if necessary.

Feedback to the PID loop can be from either a digital source forexample, but not limited to, a serialized ADC stream or an analogsignal, both of which are dependent on the output of the circuit. Thisfeedback can provide information relating regulated output current orvoltage.

Temperature Sensor. An on-board temperature sensor may be realized sothat ample protection from over temperature situations exists. Actionstaken to protect against thermal damage may include de-rating of outputpower and complete shut-down of output.

Control Circuitry. The Tronium PSSoC provides for control whetherthrough digital means or through analog circuitry. Through this controlcircuitry, the IC is able to set and change existing control thresholdsand control points as well as enable/disable specific functionality.This can be done through registers or fuses in a digital interfacesituation or through applied voltages to analog pins should analogsetting be desired.

If the feature is enabled, the Tronium PSSoC allows the output of thesystem to be disabled or de-rated. This can take place by turning offthe PWM, switch capacitor circuit, or through de-ration of either orboth subsystems. The output can be disabled as a result of errordetection or as a result of a low output current or output powersituation such as arises when a connected device that includes a batteryis done charging the battery and the Tronium PSSoC is only providingpower to the non-battery charging functionality. Once the Tronium PSSoChas entered into a low current shut-down state, it will intermittentlyre-apply output power to the end device in order to check whether or notit now requires power above certain threshold indicating that thebattery now needs further charge. The time spent in the off state may beadjusted for varying applications. FIG. 33 illustrates an example of thealgorithm for low-current detection and error detection.

The Tronium PSSoC provides multiple interfaces to external circuitry sothat devices may control and configure the IC. These interfaces caninclude, but are not limited to, SPI, I2C, UART or othersynchronous/asynchronous serial stream. Alternate encoding to NRZformats can also be realized to optimize the size and part count ofexternal circuitry. Likewise these communications interfaces can beconnected to isolation devices in order to enable communications from anisolated region should this be desired.

Clock Generator. The Tronium PSSoC may have the ability to generate itsown internal clocks which may also include frequency controllingcircuits including, but not limited to: internal Oscillators, PLLs,FLLs, clock dividers, VCOs, and trimming circuitry. Additionally theclocking tree may implement intentional clock jitter or other means tovary the clock edge placement in order to minimize the effects of theclocking on radiated and conducted EMI.

Module Description. The Tronium PSSoC is intended for use as a powersupply device which is to be incorporated into a module which accepts ACpower in, converts this power to a DC Voltage, and supplies this powerexternal devices. Alternatively, a DC input may be introduced, whichbypasses the rectification, which then produces either a DC or ACoutput. The module can take many forms, which can include either analogor digital feedback of the output to the ASIC, or the ASIC can operatein open loop mode with no feedback. Additionally, module circuitry canbe constructed so that individual outputs (should there be a pluralityof connected outputs) can be discretely monitored and controlled. Thesensing capabilities within the module are meant to supplement orreplace the measurements taken by ASIC depending on the application andregulation requirements.

FIG. 34 is a schematic of the power circuit 22 including DigitalFeedback module with isolation and discrete output sensing. FIG. 35 is aschematic illustration of the power circuit 22 including Analog Feedbackmodule with linearization of feedback isolation. These represent ananalog feedback version and a digital feedback version. Both of thesediagrams also indicate an isolation transformer as part of the design.This component may or may not be included in the module depending on therequirements of the application. Both examples describe a synchronousrectification scheme, however an asynchronous system could also berealized.

Digital Feedback Description. The digital feedback module includes amicrocontroller, standalone ADC, or secondary ASIC in order to monitorthe output voltage and to allow very precise measurements to be taken atthe output connection. This allows the module to compensate forcomponent losses, temperature, and other variables that may causevariance in the output voltage. This data is then formatted and sentback to the ASIC to provide the digital feedback stream. Current sensingand output enable transistors are also shown so that should a multitudeof outputs be connected to the module with individual sensing at each.In this manner the low power shut-off functionality described in theASIC description could be applied to individual loads even though thepower is shared.

Analog Feedback Description. If for cost or other reasons it is desiredto use an analog feedback system, the Tronium PSSoC allows this to berealized through the analog feedback input. In the embodiment shown, thecurrent through an opto-isolation LED is proportional to the outputvoltage. The circuit is designed so that the voltage at the analogfeedback pin on the IC is at nominal voltage when the output voltage isat the target output. Current monitoring is performed by the IC at theprimary side of the transformer, and the measurements are scaled by theturns ration of the transformer.

FIG. 36 is a schematic illustration of a Level Shifter circuit that maybe used with the power circuit 22. In one embodiment, the switchcapacitor voltage divider circuit 32 and the buck regulator 34 relies ona level shifter that can take a static CMOS level digital signal andvoltage shift the signal to various levels. This is done to properlydrive the gates of high voltage switches both off and on Tronium PSSoCchip. The level shifter is comprised of a differential pair with astatic dc current bias current. The diff pair amplifies the CMOS levelsignal and then shifts to a higher rail. There are cascodes used in thesignal path to avoid any transistor breakdown. The level shifter can bedisabled via a p-channel switch to avoid any static current drain. Oncethe signal is shifted to another rail, it is further amplified convertedto single ended and then converted back to static CMOS levels to drivehigh voltage switches.

FIGS. 38 and 39 are additional schematic illustrations of the powercircuit 22. In one embodiment, the forward converter transformer 102 mayinclude a tertiary winding 152 (shown in FIGS. 39 and 40) that may beused as a replica of the secondary side for current sensing. Forexample, some Tronium PSSoC applications can run at low voltages and aself driven synchronous rectifier may not be a reliable solution. Moregate voltage would ensure a robust system. For example there will be anapplication for a 1.8 Volt DC output. Assume a 12:1 transformer and a 43Volts CP_DAC2 setting, 3.6 VDC is the peak voltage on the secondarywinding. A 12:2 auxiliary winding can be used to produce 7.2 Volts ofgate drive for the synchronous rectifier FETs. The transformer designmay include the auxiliary winding 152 on the secondary side to supportthis requirement.

FIG. 41 is a schematic diagram of the power circuit 22 including a DC-DCconversion circuit. In the illustrated embodiment the power circuit 22includes the switch capacitor voltage divider circuit 32 for receiving aDC input power signal and generating a DC output power signal having alower voltage level. In one embodiment, the power circuit 22 may alsoinclude the switch-mode buck regulator 34 coupled in parallel with theSCVBC 32. The high-efficiency switch capacitor voltage divider circuit32 includes a pair of flyback capacitors electrically coupled in eitherin parallel or series, depending on whether the primary function of thatcircuit block is to reduce voltage or increase current, and a pluralityof switch assemblies that are electrically coupled to each of the pairof flyback capacitors. In one embodiment, the gates between thecapacitors are shared. The switch assemblies may be operated toselectively deliver an input DC power signal to each of the pair offlyback capacitors during a charge phase, and to selectively deliver anoutput DC power signal to an electronic device during a discharge phasethat has a lower voltage level than the input DC power signal. At leastone switch assembly may include an N-channel MOSFET switch and a levelshifter for delivering a control signal to the N-channel MOSFET switch.In addition, a charge pump may be coupled to the level shifter toreceive the input DC power signal and generate an output power signalhaving a higher voltage level than the input DC signal. The output powersignal is delivered to the level shifter for use in operating N-channelMOSFET switch (or closing for other types of MOSFETs). In addition, theswitch capacitor voltage divider circuit may include a control circuitthat includes a voltage sensing circuit for sensing a voltage level ofthe input DC power signal and a gain controller configured to select again setting of the switch capacitor voltage divider circuit as afunction of the sensed voltage level and operate each of the pluralityof switch assemblies as a function of the selected gain setting.

FIGS. 42-50 are additional schematics diagram of the electrical powercircuit 22. FIG. 51 is a schematic diagram of a voltage reductioncircuit cell 32 that may be used with the electrical power circuit 22.Referring to FIG. 42, in one embodiment, the power circuit 22 includes aDC-DC conversion circuit that includes multiple stages of voltagereduction circuit cells 32. In the illustrated embodiment, the powercircuit 22 includes a circuit input terminal 200 that is configured toreceive an input power signal, a circuit output terminal 202 that isconfigured to provide an output power signal to an electrical device,and a multi-stage voltage reduction circuit 204 that includes aplurality of voltage reduction circuit cells 32 that are coupled betweenthe circuit input terminal 200 and the circuit output terminal 202 forreceiving the input power signal and delivering the output power signalat a desired voltage level. In one embodiment, the output power signalis delivered at an output voltage level that is less than the voltagelevel of the input power signal. In another embodiment, the output powersignal may have an output voltage level that is greater than, orapproximately equal to, the voltage level of the input power signal.

In one embodiment, the multi-stage voltage reduction circuit 204provides to following: 1) Universal Vline capability: 127 v to 375 v(DC); 2) No Buck Regulator; 3) No Forward Converter; 4) 5-8 StageRegulated Charge Pump depending on the output voltage; 5) LT_Spicesimulations run for 0.5 v & 19.6 v outputs at 127 v & 375 v linevoltage; 6) 0.5 v case for 50 mA load current; 7) 19.6 v case for 200 mAload current; 8) 200 mA load current limited by Rdson/area of MOSswitches; 9) Maximum efficiency achieved when low divide ratio's areapplied to front end stages and high divide ratio's applied to the backend stages; 10) Only the final stage regulated, all other stages runningunregulated for maximum efficiency; 11) 7.5 μF fly back capacitors used;and 12) Downstream stages (˜3 stages) with 20 v devices to optimizearea.

Referring to FIG. 51, in the illustrated embodiment, the voltagereduction circuit cell 32 includes a cell input terminal 206 that isconfigured to receive a cell input power signal, a cell output terminal208 that is configured to provide an cell output power signal, a pair offlyback capacitors 70, a switching circuit 210 coupled to the flybackcapacitors 70 for delivering power from the cell input terminal 206 tothe cell output terminal 208, and a hold capacitor 36 that is coupledbetween the switching circuit 210 and the cell output terminal 208. Theswitching circuit 210 includes a plurality of switching devices 72 thatare configured to operate the voltage reduction circuit cell 32 at aplurality of operational modes including a charge mode 66 (shown in FIG.54), a discharge mode 68 (shown in FIG. 55), and a bypass mode 212(shown in FIG. 65).

In the illustrated embodiment, the power circuit 22 also includes acontroller, such as for example the power controller integrated circuit(Tronium PSSoC) 106, shown in FIGS. 16, 17A, and 17B. The controller 106is coupled to each of the voltage reduction circuit cells 32 foroperating each of the voltage reduction circuit cells 32 at theplurality of operational modes to receive the input power signal at thecircuit input terminal 200 and deliver the output power signal at thecircuit output terminal 202 at the desired voltage level. In oneembodiment, the controller 106 includes a processor for executingoperational programs for regulating the operation of the power circuit22, a memory device for storing the operational programs that areaccessible by the processor, and a database for storing various data foruse in operating the power circuit 22 according to the embodimentsdescribed herein.

In the illustrated embodiment, the multi-stage voltage reduction circuit204 includes a plurality of voltage reduction circuit cells 32 that arecoupled together in series between the circuit input terminal 200 andthe circuit output terminal 202. For example, as shown in FIG. 42, thepower circuit 22 may include a first voltage reduction circuit cell 32and a second voltage reduction circuit cell 32 that are coupled togetherin series between the circuit input terminal 200 and the outputterminal. The cell input terminal 206 of the first voltage reductioncircuit cell 32 is coupled to the circuit input terminal 200 forreceiving the input power signal. The cell output terminal 208 iscoupled to the cell input terminal 206 of the second voltage reductioncircuit cell 32 to deliver a power signal to from the first voltagereduction circuit cell 32 to the second voltage reduction circuit cell32. The cell output terminal 208 of the second voltage reduction circuitcell 32 may be connected to the circuit output terminal 202 or a cellinput terminal 206 of another voltage reduction circuit cell 32.

In the illustrated embodiment, the controller 106 operates each voltagereduction circuit cell 32 to reduce a voltage level of the power signalbeing delivered from each corresponding voltage reduction circuit cells32. For example, the controller 106 may operate the first voltagereduction circuit cell 32 to deliver an intermediate power signal to thesecond voltage reduction circuit cell 32 having a reduced voltage level,and operate the second voltage reduction circuit cell 32 to furtherreduce the voltage level of the power signal to deliver an output powersignal having a voltage level that is less than the voltage level of theintermediate power signal. In the illustrated embodiment, the controller106 operates each voltage reduction circuit cell 32 at a voltagedivision ratio, e.g., a gain setting, to sequentially reduce the voltagelevel of the input power signal to the desired voltage level of theoutput power signal.

In one embodiment, the controller 106 may include a gain selector 214that is enabled by the algorithms, which is configured to determine again setting for each voltage reduction circuit cell 32 and generate anddeliver a control signal to each voltage reduction circuit cell 32 tooperate the voltage reduction cells 32 at the corresponding gainsettings. For example, as shown in FIGS. 52-63, each voltage reductioncell circuit 32 is configured to operate in a plurality of gainsettings. For example, in one embodiment, the voltage reduction circuitcell 32 may be operated at a gain setting of 1×, ⅔×, and/or a ½ gainsetting. In one embodiment, the controller 106 may determine a gainsetting for each of the plurality of voltage reduction circuit cells 32as a function of a predefined output signal voltage level and generateand deliver the control signal to each of the voltage reduction circuitcells 32 as a function of the corresponding gain settings. In oneembodiment, the gain settings of each of the voltage reduction circuitcells 32 is selected to deliver the output power signal at a desiredvoltage level and minimize power losses through the power circuit 22.

In one embodiment, the controller 106 is configured to operate one ormore voltage reduction circuit cells 32 at different gain settings. Forexample, in one embodiment, the first voltage reduction circuit cell 32may be regulated at a first capacitive gain setting and the secondvoltage reduction circuit cell 32 may be regulated at a secondcapacitive gain setting that is different from the first capacitive gainsetting. In addition, the controller 106 may operate the first voltagereduction circuit cell 32 at a first capacitive gain setting thatincludes a voltage division ratio that is less than a voltage divisionratio of the second capacitive gain setting to facilitate reducing thelosses across each of the voltage reduction circuit cell stages andincrease the overall power efficiency of the power circuit 22. Forexample, in one embodiment, the controller 106 may operate the firstvoltage reduction circuit cell 32 at a gain setting of ⅔×, and operateeach subsequent voltage reduction circuit cell 32 at a gain setting of½×.

In the illustrated embodiment, the multi-stage voltage reduction circuit204 includes a regulated voltage reduction circuit cell 216. Thecontroller 106 is configured to regulate the control signal delivered tothe regulated voltage reduction circuit cell 216 to adjust a duty cycleof the control signal to maintain the voltage level of the output powersignal at a desired voltage level and/or within a desired voltage levelrange. In one embodiment, the controller 106 may include a regulationcontrol circuit 218 that includes a voltage scaler 220 including a pairof resistors for sensing a voltage level on the output power signal, andcomparator 222, and a clock generator 224 for generating a modulatedgated clock signal to the switching circuit 210. In one embodiment, thedesired voltage level, Vref, may be a fixed voltage level and/or bereceived from the DAC, which can be regulated or unregulated. Inaddition, Vref may be received by the controller 106 from power deviceand/or via wireless communication. The comparator 222 compares thevoltage signal received from the voltage scaler 220 with the desiredvoltage level and transmits a control signal to the clock generator 224.The clock generator receives the control signal from the comparator 222and a control clock signal and generates a gated clock signaltransmitting to the switching circuit 210.

In the illustrated embodiment, the controller 106 is configured toregulate the regulated voltage reduction circuit cell 216 independent ofthe gain setting of the regulated voltage reduction circuit cell 216.For example, in one embodiment, the gain selector 214 delivers a gainsetting control signal to provide a course setting to operate theregulated voltage reduction circuit cell 216 at a determined gainsetting, and the regulation control circuit 218 delivers a regulatedcontrol signal to provide a fine setting to regulate the regulatedvoltage reduction circuit cell 216 to deliver the output power signal atthe desired voltage level. For example, in one embodiment, regulation ofthe regulated voltage reduction circuit cell 216 may include pulseskipping to partially charge/discharge the corresponding capacitors 70.

In one embodiment, for a given input power signal voltage level, thenumber of voltage reduction circuit cells 32 that are required to reducethe input power signal voltage to the desired output voltage level isless than the total number of voltage reduction circuit cells 32included in the power circuit 22. The controller 106 may be configuredto determine a voltage level of the input power signal, determine thepredefined output signal voltage level, and determine a required numberof voltage reduction circuit cells 32 needed to deliver the output powersignal at a the desired voltage level. The controller 106 may alsodetermine a gain setting of each voltage reduction circuit cells 32 as afunction of the number of required voltage reduction circuit cells 32and the desired output power signal voltage level, and generate anddeliver control signals to each of the voltage reduction circuit cells32 as a function of the corresponding gain settings.

In one embodiment, in order to operate the power circuit 22 with therequired number of voltage reduction stages, the controller 106 mayselect one of the voltage reduction circuit cells 32 to receive theinput power signal to begin reduction of the power signal voltage level.For example, in one embodiment, the controller 106 may select an inputvoltage reduction circuit cell 226 of the multi-stage voltage reductioncircuit 204 for receiving the input power signal and operate the powercircuit 22 to deliver the input power signal to the cell input terminal206 of the selected input voltage reduction circuit cell 226. In oneembodiment, the controller 106 may identify one or more bypass voltagereduction circuit cells from the plurality of cells 32 that are coupledbetween the circuit input terminal 200 and the input voltage reductioncircuit cell 226 and operate the bypass voltage reduction circuit cellswith a gain setting of 1× (shown in FIGS. 52-55) to deliver the inputpower signal from the circuit input terminal 200 through the bypassvoltage reduction circuit cells 32 to the input voltage reductioncircuit cell 226. In another embodiment, the controller 106 may beconfigured to operate the bypass voltage reduction circuit cells in abypass mode 212 (shown in FIGS. 64-65) to deliver the input power signalthrough the bypass voltage reduction circuit cells 32 and to the inputvoltage reduction circuit cell 226. The point of the bypass circuitsbeing that the higher voltage Mux Core Cells and their devices may beavoided if the input voltage (for instance 48 volts DC rather than 110volts AC) is less than the higher voltage Mux Core Cell. For instance,if 220 AC is the input voltage, then at least a 400 volt Mux Core Cellmust be used as the first voltage division block. Then lower voltage MuxCore Cells would follow down to the target voltage output, which couldbe 2 or more conversion Mux Core Cells. However, if the input voltage islower, for instance in the case of a telecom type input signal of 48volts, then the Mux Core Cell voltage conversion blocks which havedevices and break down voltages higher than 48 volts would be avoided,so that the 1:1 gain setting, and it's associated losses would not needto be introduced into the cascade of Mux Core Cell voltage divisionblocks.

Likewise, the signal may exit at any one of the cascaded Mux Core Cellsso that a target voltage can be easily accomplished which would behigher than the lower voltage Mux Core Cells further down the chain.Also, the signal can exit at any stage of the Mux Core Cell cascade sothat a transformer can be added to the circuitry. For instance a 220 VACsignal may be the Vline input, and when a target range of voltagedivision of 50 volts has been accomplished, then the signal could beintroduced into a transformer for the final and further conversions.

In one embodiment, the power circuit 22 may include at least one of thevoltage reduction circuit cells 32 may include switching devices 72,such as for example MOSFETS, having voltage ratings that are less than avoltage rating of another voltage reduction circuit cell 32. Forexample, the first voltage reduction circuit cell 32 may include MOSFETShaving a voltage rating that is higher than the voltage rating of theMOSFETS include in the second voltage reduction circuit cell 32. Inaddition, the first voltage reduction circuit cell 32 may be operated ata gain setting that delivers the intermediate power signal at a reducedvoltage level, which enables the second voltage reduction circuit cell32 receiving the intermediate power signal to include MOSFETS with lowervoltage ratings determined as a function of the voltage level of theintermediate power signal. For example, in one embodiment, the powercircuit 22 may include 4-stages of voltage reduction circuit cells 32with gain settings of 0.5×, 0.5×, 0.5×, and 0.5×, respectively,receiving an input power signal having a line voltage, Vline,approximately equal to 373 VDC and delivering an output power signalhaving an output voltage level approximately equal to 23 VDC. In thisexample, during operation of the power circuit 22, the intermediatepower signals delivered from the cell output terminal 208 of eachvoltage reduction stage is approximately 186 VDC, 93 VDC, 47 VDC, and 23VDC, respectively. The corresponding voltage rating of the switchingdevices 72 include in each of the four stages is approximately 400V forthe 1^(st) stage, 200V for the 2^(nd) stage, 100V for the 3^(rd) stage,and 50V for an the 4^(th) stage.

Referring to FIG. 44, in one embodiment, the power circuit 22 mayinclude an input bypass circuit 228 that is connected between thecircuit input terminal 200 and each voltage reduction circuit cells 32.The input bypass circuit 228 may include a plurality of switchingdevices 72 to enable the input power signal to be delivered to any ofthe voltage reduction circuit cells 32 within the power circuit 22. Forexample, in one embodiment, the controller 106 may operate the inputbypass circuit 228 to bypass the bypass voltage reduction circuit cellsto deliver the input power signal from the circuit input terminal 200 tothe input voltage reduction circuit cell 226.

In the illustrated embodiment, the power circuit 22 may include aforward converter 96 that is coupled to the multi-stage voltagereduction circuit 204 for receiving an intermediate power signal fromthe multi-stage voltage reduction circuit 204 and deliver the outputpower signal at the desired voltage level. The power circuit 22including the multi-stage voltage reduction circuit 204 and the forwardconverter 96 delivers a power source up to 4.5 A current; requires a 2stage Charge Pump (CP); and the CP can source up to 200 mA of loadcurrent, buck not required (4 component reduced).

In addition, the power circuit 22 may be configured to deliver theintermediate power signal from any of the voltage reduction circuitcells 32 included in the multi-stage voltage reduction circuit 204. Forexample, in one embodiment, the controller 106 may select an outputvoltage reduction circuit cell from the plurality of voltage reductioncircuit cells 32 to deliver the intermediate power signal to the forwardconverter 96. The controller 106 may also select the output voltagereduction circuit cell as a function of a predefined desired outputsignal voltage level, operate the selected output voltage reductioncircuit cell to couple the output voltage reduction circuit cell to theforward converter 96 to deliver an intermediate power signal from themulti-stage voltage reduction circuit 204 to the forward converter 96,and regulate the forward converter 96 to deliver the output power signalto the circuit output terminal 202.

The controller 106 may also be configured to identify one or more bypassvoltage reduction circuit cells 32 that are coupled between the forwardconverter 96 and the output voltage reduction circuit cell and operatethe bypass voltage reduction circuit cells 32 in a bypass mode 212 orwith a 1× gain setting to deliver the intermediate power signal from theoutput voltage reduction circus cell through the bypass voltagereduction circuit cells to the forward converter 96.

In one embodiment, the power circuit 22 may include an output bypasscircuit 230 that is connected between the forward converter 96 and eachvoltage reduction circuit cells 32 to enable the intermediate powersignal to be delivered from any of the voltage reduction circuit cells32 to the forward converter 96. For example, in one embodiment, thecontroller 106 may operate to disconnect one or more bypass voltagereduction cells from the multi-stage voltage reduction circuit anddeliver the intermediate power signal from the output voltage reductioncircuit cell through the bypass circuit 230 to the forward converter 96.For example, in one embodiment, the controller 106 may open one or moreof the switching devices 72 of the selected bypass voltage reductioncircuit cell to disconnect the selected bypass voltage reduction circuitcell.

In an alternative embodiment, power circuit 22 may use, for instance,eight stages for a given output, knowing that only four stages areneeded for US (110V) or five stages for Europe (220V) to get to a targetvoltage such as, for example, 5 v, and then operate the last one of morestages to connect by circuitry these last one or more stages to boostcurrent from 10 W to 20 W.

Referring to FIG. 43, in one embodiment, the multi-stage voltagereduction circuit 204 may include two or more voltage reduction circuitcells 32 that are electrically coupled in parallel. For example, themulti-stage voltage reduction circuit 204 may include a first set 232 ofvoltage reduction circuit cells 32 that are electrically coupledtogether in series and a second set 234 of voltage reduction circuitcells 32 that are electrically coupled together in parallel. The secondset 234 of voltage reduction circuit cells 32 is configured to increasea current level of the output power signal being generated by themulti-stage voltage reduction circuit 204. In one embodiment, the secondset 234 of voltage reduction circuit cells 32 is coupled between thefirst set 232 of voltage reduction circuit cells and the circuit outputterminal 202 to facilitate increasing a current level of the outputpower signal being delivered to the circuit output terminal 202. Inanother embodiment, the second set 234 of voltage reduction circuitcells 32 may be coupled between the circuit input terminal 200 and thefirst set 232 of voltage reduction circuit cells 32. In yet anotherembodiment, the second set 234 of parallel voltage reduction circuitcells 32 may be coupled between two sets of voltage reduction circuitcells 32 coupled in series.

Referring to FIG. 45, in one embodiment, the power circuit 22 mayinclude the multi-stage voltage reduction circuit 204 and a buckregulator 34. In one embodiment, the buck regulator 34 may be coupledbetween the circuit input terminal 200 and the circuit output terminal202 and coupled in parallel with the multi-stage voltage reductioncircuit 204. In another embodiment, the buck regulator 34 may be coupledin series with the multi-stage voltage reduction circuit 204. Thecontroller 106 may be configured to operate the buck regulator 34 tofacilitate increasing a current level of the output power signal.

Referring to FIGS. 46 and 47, in one embodiment the power circuit 22 mayinclude a single-stage voltage reduction circuit 236 including onevoltage reduction circuit cell 32, a buck regulator 34, and a forwardconverter 96 coupled to the buck regulator 34 and voltage reductioncircuit cell 32. The controller 106 may be configured to determine adesired current level of the output power signal and select the buckregulator 34 or the single-stage voltage reduction circuit 236 toreceive the input power signal and deliver the intermediate power signalat a reduced voltage level to the forward converter 96. The controller106 may also regulate the forward converter 96 to receive theintermediate power signal and deliver the output power signal at thedesired voltage level. In addition, the controller 106 may be configuredto operate the buck regulator 34 and the single-stage voltage reductioncircuit 236 simultaneously to deliver the intermediate power signal tothe forward converter 96. In another embodiment, as shown in FIG. 48,the power circuit 22 may include the multi-stage voltage reductioncircuit 204 including a plurality of voltage reduction circuit cells 32,the buck regulator 34, and the forward converter 96 for delivering powersignals from the buck regulator 34 and multi-stage voltage reductioncircuit 204 to the circuit output terminal 204.

In one embodiment, shown in FIGS. 49 and 50, the power circuit 22 mayinclude a two-stage voltage reduction circuit 238 coupled to a forwardconverter 96. The two-stage voltage reduction circuit 238 includes twovoltage reduction circuit cells coupled in series. In the illustratedembodiment, the power circuit 22 includes a primary side regulationcircuit 240 for regulating the forward converter 96 to deliver theoutput power signal at a desired voltage level.

Referring to FIG. 46, in one embodiment, the power circuit 22 mayinclude a rectifier circuit 30 and an input filter capacitor 40 that iscoupled to the single-stage voltage reduction circuit 236 for providingrectified DC power single to the single-stage voltage reduction circuit236. The rectifier circuit 30 is coupled between the single-stagevoltage reduction circuit 236 and the circuit input power terminal 200for receiving an AC power signal from the input power terminal 200 anddelivering a rectified DC power signal to the single-stage voltagereduction circuit 236. Similarly, in one embodiment shown in FIG. 48,the power circuit 22 may include a rectifier circuit 30 and an inputfilter capacitor 40 coupled between the input power terminal 200 and themulti-stage voltage reduction circuit 204 for receiving an AC powersignal from the input power terminal 200 and delivering a rectified DCpower signal to the multi-stage voltage reduction circuit 204. In oneembodiment, the power circuit 22 may not include the input filtercapacitor 40, and the input filter capacitor 40 can be removed becausethe power circuit 22 can be configured to provide constant currentthrough the capacitors in the first high voltage stage 32 of thesingle-stage voltage reduction circuit 236 and/or the multi-stagevoltage reduction circuit 204.

Referring again to FIGS. 8 and 51, in the illustrated embodiment, thevoltage reduction circuit cell 32 includes a cell input terminal 206that is configured to receive an input power signal, a cell outputterminal 208 that is configured to provide an output power signal, afirst capacitor 242, a second capacitor 244, and a switching circuit 210that includes a plurality of switching devices 72 that are coupled tothe first capacitor 242 and the second capacitor 244 for deliveringpower from the cell input terminal 206 to the cell output terminal 208.The voltage reduction circuit cell 32 also includes a hold capacitor 36that is coupled between the switching circuit 210 and the cell outputterminal 208. The cell output terminal 208 is configured to be coupledto a cell input terminal 206 of another voltage reduction circuit cell32 to facilitate use of the voltage reduction circuit cell 32 in amulti-stage voltage reduction circuit 204. Each capacitor 242, 244, 36includes a positive top plate 246 and a negative bottom plate 248. Thecontroller 106 is coupled to the switching circuit 210 and is configuredto operate the switching circuit 210 in a plurality of operational modesto deliver an output power signal at a desired voltage level.

In the illustrated embodiment, the voltage reduction circuit cell 32includes nine switching devices 72 (S1, S2, S3, S4, S5, S6, S7, S8, S9).In the illustrated embodiment, each switching device 72 includes aMOSFET switch having a source, drain, and gate. In one embodiment, eachswitching device 72 includes an N-channel MOSFET. In another embodiment,one or more switching devices 72 includes a P-channel MOSFET. As shownin FIG. 51, the switching circuit 210 includes at least two switchingdevices 72 (e.g., S5, S9) that are coupled to ground. For example, theswitching circuit 210 includes a first switching device 250 (e.g., S5)that is coupled to the first capacitor 242 for coupling the negativeplate 248 of the first capacitor 242 to ground and includes a secondswitching device 252 (e.g., S9) that is coupled to the second capacitor244 for coupling the negative plate 248 of the second capacitor 244 toground. The switching circuit 210 also includes a set of switchingdevices 72 (e.g., S1, S3, S7) having corresponding drains that arecoupled to the cell input terminal 206, and a different set of switchingdevices 72 (e.g., S2, S4, S8) having the corresponding sources that arecoupled to the cell output terminal 208. In addition, the switchingdevice 72 includes a first set 254 of switching devices 72 (e.g., S1,S3, S7) that are coupled between the cell input terminal 206 and thefirst and second capacitors 240, 242, and a second set 256 of switchingdevices 72 (e.g., S2, S4, S8) that are coupled between the first andsecond capacitors 242, 244 and the cell output terminal 208. Theswitching circuit 210 includes at least two switching devices 72 (e.g.,S1, S2) that are coupled to the positive plate 246 of the firstcapacitor 242 and at least two different switching devices (e.g., S6,S7) that are coupled to the positive plate 246 of the second capacitor244. The switching circuit 210 also includes at least one switchingdevice 72 (e.g., S6) that is coupled between the negative plate 248 ofthe first capacitor 242 and the positive plate 246 of the secondcapacitor 244.

In the illustrated embodiment, each switching device 72 includes a levelshifter 92, with one or more of the switching devices 72 also inducing acharge pump 94 coupled to the corresponding level shifter 92. In oneembodiment, the switching circuit 210 may include a charge pump 94coupled to each level shifter 92. In another embodiment, as shown inFIG. 51, the switching circuit 210 may include one or more shared chargepumps 94 that are coupled to two or more switching devices 72 such thatthe total number of charge pumps 94 included in the switching circuit210 is less than a total number of switching devices 72.

In addition, the voltage reduction circuit cell 32 may be operated at again setting that delivers a power signal at a reduced voltage level,which enables at least some of the switching devices 72 included in theswitching circuit 210 to include lower voltage ratings than otherswitching devices 72 included in the switching circuit 210. For example,in one embodiment, the switching circuit 210 may include a set ofswitching devices 72, e.g S4, S5, S8, and S9 that has lower voltagerating than the other switching devices 72, e.g., S1, S2, S3, S6, andS7.

FIGS. 52-55 are schematic diagrams of the voltage reduction circuit cell32 with a 1× gain setting, FIGS. 56-59 are schematic diagrams of thevoltage reduction circuit cell 32 with a ⅔× gain setting, FIGS. 60-63are schematic diagrams of the voltage reduction circuit cell 32 with a ½gain setting, FIGS. 64 and 65 are schematic diagrams of the voltagereduction circuit cell 32 in a bypass mode, and FIG. 69 is a data tableillustrating gain settings for use with the voltage reduction circuitcell 32.

In the illustrated embodiment, the voltage reduction circuit cell 32 isconfigured to operate in a plurality of operation modes. The controller106 is coupled the switching circuit 210 and is configured to operatethe switching circuit 210 in a plurality of operational modes to deliverthe output power signal at a desired voltage level. For example, asshown in FIGS. 52-63, the controller 106 is configured to operate thevoltage reduction circuit cell 32 between a charge mode 66 and adischarge mode 68. In addition, the controller 106 may select a gainsetting associate with the voltage reduction circuit cell 32 and delivera control signal to the switching circuit 210 to operate the voltagereduction circuit cell 32 between the charge mode 66 and the dischargemode 68 at the selected gain setting. As shown in FIG. 52, thecontroller 106 may be configured to deliver a controller signal having afirst clock phase, Φ₁, and a second clock phase Φ₂. As shown in FIG. 69,the controller 106 may determine the clock phase signal delivered toeach of the switching devices 72 as a function of the selected gainsetting for the voltage reduction circuit cell 32.

Referring to FIGS. 54, 58, and 62, the controller 106 configured tooperate the switching circuit 210 in the charge mode 66 to couple apositive plate 246 of each of the first and the second capacitors 242,244 to the cell input terminal 206 and to couple a negative plate 248 ofeach of the first and the second capacitors 242, 244 to the holdcapacitor 36. For example, referring to FIGS. 9 and 51, in the chargemode 66, the controller 106 operates switching devices S1, S4, S7, andS8 to an “on” position, and operates switching devices S2, S3, S5, S6,and S9 to an “off” position.

FIGS. 52 and 53 illustrate the operational states of the switchingdevices 72 for a gain setting of 1×. FIG. 55 illustrates the voltagereduction circuit cell 32 in the discharge mode 68 to achieve a voltagedivision of 1×. In the illustrate embodiment, as shown in FIGS. 52-55,the voltage reduction circuit cell 32 is configured to operate with again setting of 1×. For example, to achieve a gain setting of 1×, thecontroller 106 is configured to operate the switching circuit 210 in thedischarge mode 68 to couple the cell input terminal 206 to the negativeplate 248 of the first capacitor 242 and to the positive plate 246 ofthe second capacitor 244, to couple the negative plate 248 of the secondcapacitor 244 to ground, and to couple the positive plate 246 of thefirst capacitor 242 to the hold capacitor 36. Referring to FIGS. 9 and51, in the discharge mode 68, for a gain setting of 1×, the controller106 operates switching devices S2, S3, and S7 to the “on” position, andoperates switching devices S1, S4, S5, S6, S8, and S9 to the “off”position. In one embodiment, referring to FIG. 69, to operate thevoltage reduction circuit cell 32 between the charge mode 66 (shown inFIG. 54) and the discharge mode 68 (shown in FIG. 55) to achieve avoltage reduction of 1×, the controller 106 may operate a first set ofswitching devices 72 (e.g., S1, S4, S8) in the first clock phase, Φ₁, anoperate a second set of switches 72 (e.g., S2, S3) in the second clockphase, Φ₂.

FIGS. 56 and 57 illustrate the operational states of the switchingdevices 72 for a gain setting of ⅔×. FIG. 59 illustrates the voltagereduction circuit cell 32 in the discharge mode 68 to achieve a voltagedivision of ⅔×. In the illustrated embodiment, to achieve a gain settingof ⅔×, the controller 106 operates the switching circuit 210 in thedischarge mode 68 to couple the positive plate 246 of the firstcapacitor 242 to the hold capacitor 36, to couple the negative plate 248of the first capacitor 242 to the positive plate 246 of the secondcapacitor 244, and to couple the negative plate 248 of the secondcapacitor 244 to ground. Referring to FIGS. 9 and 56, in the dischargemode 68, for a gain setting of ⅔×, the controller 106 operates switchingdevices S2, S6, and S9 to the “on” position, and operates switchingdevices S1, S3, S4, S5, S7, and S8 to the “off” position. In addition,as shown in FIGS. 56 and 59, to operate the voltage reduction circuitcell 32 between the charge mode 66 (shown in FIG. 58) and the dischargemode 68 (shown in FIG. 59) to obtain a voltage division of ⅔×, thecontroller 106 may operate a first set of switching devices 72 (e.g.,S1, S4, S7, S8) in the first clock phase, Φ₁, an operate a second set ofswitches 72 (e.g., S2, S6, S9) in the second clock phase, Φ₂.

FIGS. 60 and 61 illustrate the operational states of the switchingdevices 72 for a gain setting of ½×. FIG. 63 illustrates the voltagereduction circuit cell 32 in the discharge mode 68 to achieve a voltagedivision of ½×. In the illustrated embodiment, to achieve a gain settingof ½×, the controller 106 operates the switching circuit 210 in thedischarge mode 68 to couple the positive plate 246 of the firstcapacitor 242 to the hold capacitor, to couple the negative plate 248 ofthe first capacitor 242 to ground, and to coupled the negative plate ofthe second capacitor 244 to ground. Referring to FIGS. 9 and 60, in thedischarge mode 68, for a gain setting of ½×, the controller 106 operatesswitching devices S2, S5, and S9 to the “on” position, and operatesswitching devices S1, S3, S4, S6, S7, and S8 to the “off” position. Inaddition, as shown in FIGS. 60 and 63, to operate the voltage reductioncircuit cell 32 between the charge mode 66 (shown in FIG. 62) and thedischarge mode 68 (shown in FIG. 63) to obtain a voltage division of ½×,the controller 106 may operate a first set of switching devices 72(e.g., S1, S4, S7, S8) in the first clock phase, Φ₁, an operate a secondset of switches 72 (e.g., S2, S5, and S9) in the second clock phase, Φ₂.

In the illustrated embodiment, the voltage reduction circuit cell 32 isconfigured to deliver a power signal in capacitive isolation tofacilitate preventing the cell input terminal 206 from being connecteddirectly to the cell output terminal 208 during operation between acharge mode 66 and a discharge mode 68. For example, the controller 106may be configured to determine a gain setting of the voltage reductioncircuit cell 32, select a subset of the plurality of switching devices72 as a function of the gain setting, determine an operational state ofeach switching device 72 included in the selected subset of switchingdevices 72 as a function on the gain setting, and operate each switchingdevice 72 included in the subset of switching devices 72 to maintain thecorresponding operational state during the charge mode 66 and thedischarge mode 68 to facilitate capacitive isolation.

In one embodiment, in order to achieve capacitive isolation and use themultiple stages of the Mux Core Cell (i.e., the voltage reductioncircuit cell 32), the controller must be regulated by the clock as shownin FIG. 52 to ensure that all the gates in each Mux Core Cell 32 arenever closed at the same time, and that they are never closed in eachMux Core Cell 32 of a cascade. In addition, there exist a sensingmechanism regulated by the controller to constantly check forovervoltage, which would be a sign of a short. If the system shouldmalfunction and the Mux Core Cell 32 transistors would all be closed(i.e S1, S2, S3 and S4 were all closed at the same time), the an alarmevent would occur and the system would shut itself down through afailsafe circuit which would prevent the chip from accepting any moresignal from the source at VLine. In addition, a fuse can be used as athird backup of this system. In this fashion, multiple cascades of theMux Core Cell 32 can become capacitive isolation which can do thecomplete voltage division to the target output voltage and would notneed a transformer, and thus be a transformerless power system.

In one embodiment, the operation state is selected between an “on” stateand an “off” state. For example, referring to FIGS. 52, 53, and 55, fora gain setting of 1×, the controller 106 selects the subset of switchingdevices 72 including S5, S6, S7, and S9, determines the operationalstate for switch S7 to be an “on” state and determines the operationalstate for switches S5, S6, and S9 to be the “off” state, and operatesthe selected switches at the selected state during operation of thevoltage reduction circuit cell 32 between the charge mode 66 and thedischarge mode 68. For example, upon selecting the operational states ofthe selected switches, the controller 106 operates the voltage reductioncircuit cell 32 as shown in FIG. 53 to obtain a gain setting of 1×.

Similarly, referring to FIGS. 56, 57 and 59, for a gain setting of ⅔×,the controller 106 selects the subset of switching devices 72 includingS3 and S5, determines the operational state for switches S3 and S5 to bethe “off” state, and operates the selected switches at the selectedstate during operation of the voltage reduction circuit cell 32 betweenthe charge mode 66 and the discharge mode 68. For example, uponselecting the operational states of the selected switches, thecontroller 106 operates the voltage reduction circuit cell 32 as shownin FIG. 57 to obtain a gain setting of ⅔×.

In addition, referring to FIGS. 60, 61, and 63, for a gain setting of½×, the controller 106 selects the subset of switching devices 72including S3 and S6, determines the operational state for switches S3and S6 to be the “off” state, and operates the selected switches at theselected state during operation of the voltage reduction circuit cell 32between the charge mode 66 and the discharge mode 68. For example, uponselecting the operational states of the selected switches, thecontroller 106 operates the voltage reduction circuit cell 32 as shownin FIG. 61 to obtain a gain setting of ½×.

In one embodiment, referring to FIGS. 64 and 65, the controller 106 maybe configured to operate the voltage reduction circuit cell 32 in abypass mode 212. During operation in the bypass mode 212, the controller106 operates the switching circuit 210 to couple the positive plate 246and the negative plate 248 of the first capacitor to the cell inputterminal 206 and to the cell output terminal 208 to short the firstcapacitor 242 and to disconnect the second capacitor 244 from each ofthe cell input terminal 206, the cell output terminal 208, and the firstcapacitor 242. In addition, in the bypass mode 212, the source and drainof the switching devices 72 associated with the first capacitor 242 areshorted in parallel. In one embodiment, the controller 106 may closeswitching devices S1 and S2 to provide a bypass current path and closeswitching devices S3 and S4 to increase the current. The controller 106may also disconnect one side connection to the hold capacitor, Chold, toground, so that Chold would not fill, but the voltage/current would passto the next stage. In another embodiment, during the bypass mode 212,the controller 106 may operate the voltage reduction circuit cell 32with a gain setting of 1× to pass the power signal to the next stage.

In the illustrated embodiment, the controller 106 may also be configuredto regulate the switching circuit 210 to adjust a gain setting of thevoltage reduction circuit cell 32. For example, in one embodiment, thecontroller 106 may be configured to sense a voltage level of the outputpower signal and generate a control signal delivered to the plurality ofswitching devices 72 as a function of the voltage level of the outputpower signal to operate at a selected gain setting, and adjust a dutycycle of the control signal to maintain the voltage level of the outputpower signal at the desired voltage level. In addition, the controller106 may sense a current level of the output power signal and adjust theduty cycle as a function of the sensed current level. The controller 106may also be configured to sense a voltage level of the input powersignal and generate a control signal delivered to the plurality ofswitching devices as a function of the voltage level of the input powersignal, and adjust a duty cycle of the control signal to maintain thevoltage level of the output power signal at the desired voltage level.

FIG. 66 is a schematic diagram of the buck regulator circuit 34 that maybe used with the power circuit 22. The buck regulator circuit 34includes a switching device 258, a diode 260, an inductor 262, acapacitor 264, and a buck regulator control circuit 266 including withthe controller 106 for operating the switching device 258 to regulateoutput signal delivered by the buck regulator circuit 34.

FIG. 67 is a schematic diagram of a modified voltage reduction circuitcell 268 that includes a voltage reduction circuit cell 32 and anintegrated buck regulator circuit 270. In the illustrated embodiment,the voltage reduction circuit cell 32 may be configured to function asthe MOSFET switch for an external buck converter as well as incorporatethe diode and capacitor. Thus, a voltage reduction circuit cell 32 maybe reconfigured to function as the MOSFET switch for an external buckconverter 34. The external buck converter 34 may be employed when morepower is required in excess of what the multi-stage voltage reductioncircuit 204 can provide. Utilizing the existing switches (transistors,Charge Pump Drivers and Level Shifters) from a voltage reduction circuitcell 32 eliminates the need for an external high voltage MOSFET and itsassociated gate driver. Referring to FIGS. 66 and 67, the twosemiconductor components Sb and Db can be replicated using thecomponents present in the voltage reduction circuit cell 32. Therebyreducing component cost and reducing board space. In addition, thecapacitors existing externally for the voltage reduction circuit cell 32can also be used for Buck Capacitor, Cb.

For example, in one embodiment, the buck converter switch Sb may bereplaced by S1. For more current capability, switches S1 and S2 inparallel with S3 and S4 would be employed. The reverse polarity diode Dbwould be implemented using either S5 or S8. The existing hold capacitorwould be used in connection with the (external or internal) inductor. Inaddition, the reverse protection diode is inherent in the channelstructure of the MOSFET. The internal nodes of the voltage reductioncircuit cell 32 are accessible for connection to Lb because capacitorsC1, C2 and C3 are external components implying external package pinsexist for these nodes. The voltage reduction circuit cell 32 alreadycontains the Dickson charge pumps and associated systems required fordriving the high voltage biased MOSFET gates. Alternatively, a diodecould exist above C3 which would provide the diode for the Buck, andalso be used during Bypass Mode as the block to the capacitor if allfour switches are used, which is then called a BUX™ circuit as itinternally provides devices for the Buck operation from the MuxcapacitorCore Cell™, as shown in FIGS. 66 and 67.

In another aspect of the invention a Muxcapacitor Core Cell (MCC) can bereconfigured to function as the MOSFET switch for an external buckconverter as well as incorporate the diode and capacitor from existingMCC features.

Thus, a Muxcapacitor stage can be reconfigured to function as the MOSFETswitch for an external buck converter. The external buck converter isemployed when more power is required in excess of what the Muxcapacitorstages can provide. Utilizing the existing switches (transistors,Dickson Charge Pump Drivers and Level Shifters) from a MCC (this methodis called the “BUX”) eliminating the need for an external high voltageMOSFET and its associated gate driver. FIG. 66 shows a typical buckconverter with the following external components: Sb, Db, Lb and Cb.

As shown in FIG. 67, the two semiconductor components Sb and Db can bereplicated using the components present in a Muxcapacitor Core Cell.Thereby reducing component cost and reducing board space. In addition,the Caps existing externally for the MCC can also be used for Buck Cap,Cb. Referencing the Muxcapacitor schematic shown in FIG. 67, (Mux CoreCell) the buck converter switch Sb can be replaced by S1. For morecurrent capability, switches S1 and S2 in parallel with S3 and S4 wouldbe employed. The reverse polarity diode Db would be implemented usingeither S5 or S8. The existing Hold Cap would be used in connection withthe (external or internal) inductor. In addition, the reverse protectiondiode is inherent in the channel structure of the MOSFET. The internalnodes of the Muxcapacitor are accessible for connection to Lb becausecapacitors C1, C2 and C3 may be external components implying externalpackage pins exist for these nodes. If they are internal capacitors,then internal circuitry would make the connection. The Muxcapacitor CoreCell already contains the Dickson charge pumps and associated systemsrequired for driving the high voltage biased MOSFET gates.Alternatively, a diode could exist above C3 which would provide thediode for the Buck, and also be used during Bypass Mode as the block tothe Cap if all four switches are used.

In one embodiment, the buck converter switch Sb is replaced by S2. Formore current capability, switches S1 and S2 in parallel with S3 and S4would be employed using V_(IN) as the input point. The reverse polaritydiode Db would be implemented using D₁. The existing hold capacitor, C3would be used in connection with the external inductor L₁ in order tocomplete the buck circuit instead of an additional external capacitor,as is typically seen in a buck configuration. In addition, thisconfiguration helps implement the “ByPass Mode” of operation. The ByPassMode is used typically where a higher voltage reduction circuit cell 32is bypassed and the input is started further down the multi-stagevoltage reduction circuit chain. This method is used when the originalV_(IN) is a lower input voltage (i.e., 48 volt input would bypass twovoltage reduction cells in order to avoid transistor losses associatedwith 1:1 conversions). Thus, closing S₁₀ allows the inductor to beshorted to remove it from the multi-stage voltage reduction circuit.Also, S₁₁ is opened to disconnect C₃ in the ByPass mode.

FIG. 68 is a flowchart of a method 300 that may be used to operate thepower circuit 22 for powering electronic devices. FIGS. 69 and 70 areexemplary data records that may be used by the controller 106 foroperating the power circuit 22 using method 300. The method 300 includesa plurality of steps. Each method step may be performed independentlyof, or in combination with, other method steps. Portions of the methodsmay be performed by any one of, or any combination of, the components ofthe controller 106.

In the illustrated embodiment, in method step 302, the controller 106receives an input power signal at the circuit input terminal, senses avoltage level of the input power signal, and determines a desiredvoltage level of the output power signal to be delivered to the circuitoutput terminal 202.

In method step 304, the controller 106 determines the number of voltagereduction stages to be operated in the multi-stage voltage reductioncircuit 204 to deliver the output power signal at the desired voltagelevel. For example, in one embodiment, the controller 106 may determinea required number of voltage reduction circuit cells 32 that may be usedto reduce the voltage level of the input power signal and to deliver theoutput power signal at a voltage level approximately equal to thedesired output signal voltage level. In addition, the controller 106 maybe configured to determine the required number of voltage reductioncircuit cells as a function of the sensed voltage level of the inputpower signal. For example, in one embodiment, the controller 106 maysense the voltage level of the input power signal and access a stageselection table 272 (shown in FIG. 70) being stored in the database. Thecontroller 106 then selects the number of required stages as a functionof the input power signal voltage level.

In method step 306, the controller 106 selects an input voltagereduction circuit cell 226 and an output voltage reduction circuit cellas a function of the selected number of stages.

In method step 308, the controller 106 determines a gain setting foreach voltage reduction circuit cell 32 included in the selected numberof stages. For example, the controller 106 may access the stageselection table 272 to select a gain setting for each voltage reductioncircuit cell as a function of a the desired output signal voltage leveland the sensed input power signal voltage level. The controller 106 maygenerate a control signal being delivered to each of the voltagereduction circuit cells 32 as a function of the corresponding gainsettings. For example, in one embodiment, the controller 106 may accessa gain setting table 274 (shown in FIG. 69) being stored in thedatabase, and select the phased control signal to be delivered to thevoltage reduction circuit cells 32 and function of the correspondingselected gain setting.

In method step 310, the controller 106 determines a regulated voltagereduction stage from the multi-stage voltage reduction circuit for usein providing a fine-tune regulation of the output power signal.

In method step 312, the controller 106 operates the selected stages ofthe multi-stage voltage reduction circuit to deliver the output powersignal at the desired voltage level, senses a voltage level of theoutput power signal, and regulates the control signal being delivered tothe regulated voltage reduction circuit cell to adjust a duty cycle ofthe control signal to maintain the voltage level of the output powersignal at the predefined output signal voltage level.

In one embodiment, the controller 106 may select at least one bypassvoltage reduction circuit cell of the plurality of voltage reductioncircuit cells as a function of the required number of voltage reductioncircuit cells, and operate the at least one bypass voltage reductioncircuit cell to deliver the input power signal to the input voltagereduction circuit cell. The controller 106 may also select an outputvoltage reduction circuit cell from the plurality of voltage reductioncircuit cells as a function of a predefined output signal voltage level,operate the selected output voltage reduction circuit cell to couple theoutput voltage reduction circuit cell to the forward convert to deliveran intermediate power signal from the plurality of voltage reductioncircuit cells to the forward converter, and regulate the forwardconverter to deliver the output power signal to the output terminal.

FIGS. 71-74 are schematic illustrations of the primary side regulationcircuit 240 that may be used to regulate the forward converter 96included with the power circuit 22. In the illustrated embodiment, theforward converter 96 includes a transformer 102 for receiving powersignals from the voltage reduction circuit 204 and generating the outputpower signal. The primary regulation circuit 240 is coupled to a primaryside of the transformer 102 and includes a primary side switching device278 that is coupled to the primary winding of the transformer 102, acurrent sense circuit 280 that is configured to sense a current level onthe primary side of the transformer 102, a capacitor 282 that is coupledto the primary side of the transformer 102, and a regulating controller284. The primary side switching device 278 may include a MOSFET. In oneembodiment, the current sense circuit 280 may be configured to sense adifferential voltage across a resistor 286 that is coupled in serieswith the primary side switching device 278 for use in determining acurrent level on the primary side of the transformer 102. The regulatingcontroller 284 is configured to generate a pulse-width modulated (PWM)control signal that is delivered to the switching device 278 as afunction of the sensed current level to regulate the transformer todeliver the output power signal at a desired voltage level. In oneembodiment, the regulating controller 284 may be included withcontroller 106. In addition, the regulating controller 284 include afiltering control circuit 288 for generating a filtered PWM controlsignal for use in regulating the forward converter 96. The capacitor 282coupled to the transformer 102 and to ground and is configured to resetthe transformer after each transformer cycle. In the illustratedembodiment, the capacitor 282 may be coupled between the switchingdevice 278 and a primary winding of the transformer 102.

The primary side regulation circuit 240 provides the following: 1)Output Regulation for a Wide Current Range (50 mA to 4.5 A); 2)Independent of Output Voltages, Input Voltages & Process; 3) Can beimplemented for Both Forward and Fly Back Converters, Digital PSRtrimmed for temperature drift due to external components; and 4) NoAuxiliary Winding or special transformers needed.

In one embodiment, the primary side regulation circuit 240 may include avoltage sense circuit 290 that is coupled to the primary side of thetransformer 102 for sensing a differential voltage level across theprimary winding of the transformer 102. The regulating controller 284may be configured to generate the pulse-width modulated control signalas a function of the sensed voltage level. In addition, the primary sideregulation circuit 240 may include a temperature sense circuit 292 forsensing a temperature of the electrical power circuit 22. The regulatingcontroller 284 may be configured to generate the pulse-width modulatedcontrol signal as a function of the sensed temperature.

During operation of the forward converter 96, the regulating controller284 is configured to sense a current level of the primary side of thetransformer 102, generate a pulse-width modulated control signal as afunction of the sensed current level, and transmit the pulse-widthmodulated control signal to the switching device 278 to operate theswitching device 278 to regulate the transformer to deliver the outputpower signal at a desired voltage level.

FIG. 75 is a flowchart of a method 400 that may be used to operate theprimary side regulation circuit 240 to regulate the forward converter 96for powering electronic devices. FIG. 76 is another flowchart of amethod 500 that may be used to operate the primary side regulationcircuit 240. FIGS. 78 and 79 are exemplary data records that may be usedfor operating the primary side regulation circuit 240. The method 400includes a plurality of steps. Each method step may be performedindependently of, or in combination with, other method steps. Portionsof the methods may be performed by any one of, or any combination of,the components of the controller 106. FIG. 77 illustrates a plurality ofplots displaying the timing relationship of operational parameters usedin operating the primary side regulation circuit 240. FIG. 77 includes afirst plot 294 of the gate signal to the primary switching device 278, asecond plot 295 of the source of the primary side switching device 278,a third plot 296 of the drain of the primary side switching device 278showing reset, and a fourth plot 297 of the secondary side output of theforward converter 96.

In method step 402 the regulating controller 284 is configured to sensea current of the primary side of the transformer and select a valuewindow. In one embodiment, the regulating controller 284 may include apredefined range of current values included within a plurality of valuewindows. Each of the value windows includes a subset of current valueswithin the predefined range of current values. The regulating controller284 is configured to sense a current level on the primary side of thetransformer 102, select a value window from the plurality of valuewindows as a function of the sensed current level, and generate thepulse-width modulated control signal as a function of the selected valuewindow. For example, in one embodiment, the regulating controller 284senses a current level of the primary side of the transformer 102,selects a value window from the plurality of value windows as a functionof the sensed current level, determines a low window value associatedwith the selected value window, and determines a reference voltage valueas a function of the determined low window value. The regulatingcontroller 284 then generates a duty cycle modulated pulse as a functionof the reference voltage value and delivers the duty cycle modulatedpulse to the primary side switching device 278 to adjust the voltagelevel of the output power signal. In one embodiment, the regulatingcontroller 284 may sense a peak current level during a pulse of theswitching device 278 and select the value window as a function of thepeak current level. The regulation circuit 240 may also sense atemperature of the power circuit 22 and/or the power device anddetermine the low window value as a function of the sensed temperature.

For example, in one embodiment, the regulating controller 284 may beimplemented by the controller 106 and include a processor, a memorydevice, and a database. The memory device is configured to store aregulation data tables (shown in FIGS. 78 and 79) in the database foruse in generating the PWM signal being delivered to the switching device278. For example, in one embodiment, the database stores a windowselection table 298 (shown in FIG. 78) that includes a range of currentvalues and a plurality of value windows associated with the range ofcurrent values. Each of the value windows including a subset of currentvalues within the range of current values. The regulating controller 284may be sense a current level on the primary side of the transformer 102and access the window selection table 298 to select a value window as afunction of the sensed current.

In method step 404, the regulating controller 284 determines a lowwindow value. For example, in one embodiment, the regulating controller284 accesses the window selection table 298 and selects the low windowvalue, winlow, as a function of the selected value window. In oneembodiment, the database may store gain-offset selection table 299(shown in FIG. 79) that includes a plurality of gain factors, gain_N,and offset values, offset_N, associated with each value window. Theregulating controller 284 selects the gain and offset values from thegain-offset selection table 299 as a function of the selected valuewindow for use in determining winlow.

In method step 406, the regulating controller 284 senses a differentialvoltage across the primary winging and determine a reference voltage asa function of the sensed voltage. For example, the regulating controller284 may sense a differential voltage across the primary winding of thetransformer 102 and determines the reference voltage value as a functionof the low window value and the sensed differential voltage level. Theregulating controller 284 may also determine a high window valueassociated with the selected value window as a function of the lowwindow value and determining the reference voltage value as a functionof the low window value and the high window value. The regulatingcontroller 284 may also be configured to sense a peak voltage of theprimary side of the transformer and determine the reference voltage as afunction of the sensed peak voltage, the low window value, and the highwindow value.

In method step 408, the regulating controller 284 generates a duty cyclemodulated pulse as a function of the reference voltage to drive theprimary side switching device 278.

In one embodiment, the regulating controller 284 may implement method500 (shown in FIG. 76) to generate a duty cycle modulated pulse whichdrives the primary side external FET to maintain regulation for theforward converter 96. In one embodiment, the regulating controller 284continually senses voltage, current and temperature with a 12 bit ADC.External Thermistor (RTD100) is used as the transducer. The currentsensor senses the differential voltage across the 0.1Ω (vcs-gnd)resistor coupled in series with the primary side FET, and selects theone value window of the N number windows included in the windowselection table 298 (e.g., N=64 windows). The regulating controller 284then selects the gain and offset values associated with the selectedvalue window from the gain-offset selection table 299 and uses thetemperature sensor's digitized output (tempout) to calculate the winlowvalue.

The regulating controller 284 is configured to determine the low windowvalue, winlow, as a function of the sensed temperature by accessing thegain-offset selection table 299 to determine a gain value, gain_N, andan offset, offset_N, and uses the temperature sensor's digitized output(tempout) to calculate the winlow value using the following equation:winlow=gain_N*tempout+offset_N  Equation No. 1:

-   -   wherein: N is the corresponding value window Number        -   winlow is a 12 bit value for the low end of the selected            window,        -   gain_N is a Gain factor (slope) for the selected window;        -   offset_N is a Offset for the selected window (12 bit word);            and        -   tempout is the temperature sensor's digitized output.

The regulating controller 284 the calculates a high window value,winhigh, using the following equation:winhigh=winlow+128  Equation 2:

The regulating controller 284 then applies winlow and winhigh to ananalog window comparator. The window comparator uses the voltage sensoroutput, compares it against winlow & winhigh and drives a 12 bit up/downcounter running at 100 KHz. For example, regulating controller 284 theuse the voltage sensor to sense the differential voltage across theprimary winding (vp−vn) when PWM signal is low (as shown in FIG. 77) foruse in driving the 12 bit up/down counter.

The regulating controller 284 then determines a 12 bit DAC VoltageOutput value that may be used to generate a duty cycle modulated pulseusing the following equations:vref=compwin+winlow  Equation No. 3:

-   -   wherein: compwin is a 12 bit counter output; and        -   Vref is a reference voltage.            pwm=curoutd−compwin+winlow  Equation No. 4:    -   wherein: pwm is a Digital word (12 bit) to represent a specific        duty cycle; and        -   curoutd is a Current sensor digitized output.            pwm_f=pwm*A+Be ^(−st) +Ce ^(−2st)/1−e ^(−st)  Equation No.            5:    -   wherein: pwm_f is a Filtered version of pwm; and        -   A=0.3242996010650, B=−0.630903037675, C=0.321218709338; and        -   e=exponent function.            dacout=pwm*lsb+reflow  Equation No. 6:    -   wherein: lsb: 12 bit DAC least significant bit voltage level;        and        -   reflow: Low reference for the 12 bit DAC.

The regulating controller 284 then operates the comparator to comparedacout with a 100 KHz saw-tooth to generate a duty cycle modulated pulsewhich drives the primary side external FET to maintain regulation. Inthe illustrated embodiment, the regulating controller 284 generates anew duty cycle modulated pulse based on the sensed data for each pulseof the switching device 278. The regulation controller 284 may also beconfigured to conduct a device parametric compensation includingdetermining a device trim and device compensation component losscompensation. For example, the Tronium chip along with other externalcomponents on the board have tolerance variations. The Tronium chip hasa register to allow for a small correction to compensate for thesedevice-to-device variations.

In one embodiment, the primary side regulation algorithm used by theregulation controller 284 is based upon dividing the 50 mA to 4.5 Aoutput current range into “coarse” windows which contain multiple “fine”windows. These windows would be replicated for each current output rangehigher than 4.5 A, for instance 4.5 A TO 100 A. Each window has acertain gain and offset stored in some type of accessible memory. Theprimary function of the coarse windows is that once a range of voltagehas been selected by the controller selecting a certain coarse window,then the on-going re-calculations revolves around that window, and doesnot involve other coarse windows. In other words if there were tencoarse windows, each with a twenty fine windows inside, the controllerwould only look to choose a fine window within the preexisting,pre-identified coarse window, without resorting to looking at all coarsewindows. Only when the reference voltage/current has either risen ordropped sufficiently to no long be in the coarse reference window wouldthe logic start looking at all coarse windows again. In this fashion thelogic does not have to originally look at all windows, but only withinthe previously selected range. Each window has a unique offset and gainfactor which is determined via simulations which would establish thegain factor or other behavioral model or characterization for a givenapplication and for a given type of converter (Forward, Cúk, Flyback,SEPIC, etc.). The number of windows which is established is a functionof the accuracy requirement. If the accuracy is relaxed then the numberof windows is reduced. Up to 64 windows can be specified in the initialproposed architecture, but any number supported by the logic andfirmware could be selected. Simulations show that 49 windows arerequired to obtain ±0.5% accuracy within the 50 mA to 4.5 A range. ThePSR Loop begins acquisition in Soft Start mode which brings the outputvoltage close to 5 v. The Current Sensor then starts and the 12-bit ADCdigitizes the current sensor output when PWM is high. This result is thethreshold which is used to select of 1 out of 49 windows. When aparticular window is selected, its offset and gain are used to calculatea reference value which is then used to drive the PWM output. Thedigitized Voltage Sense output is also used to drive a digital windowcomparator in order to fine tune the reference value for the PWMdetermined by the Current Sense measurement. The reference value isfiltered and applied to a 12-bit DAC which drives the PWM which drivesthe external FET switch.

In one embodiment, the primary side regulation circuit 240 uses twotypes of windows which are in actuality, settings coarse and fine. Theseare selected based on the “sense” of the Primary Side input. Theseselectable ranges are Coarse Windows (CW) and within each CW is otherselectable settings which are calling Fine Windows (FW). The PSR Windowsinvention and innovation in the TRONIUM™ Power Supply System(s) on aChip™ (PSSoC™).

The primary side regulation circuit 240 is configured with a “forwardcontroller” configuration, as that is the most efficient topology.However, this invention can also be configured to work with “flyback”topologies, or topologies such as the SEPIC, Cúk, Push-Pull. With theSemitrex™ PSR Windows based primary side sensing and control, the powersupply can avoid all the opto-isolation parts, and reduce the topologyby up to a 10 part count. This is very desirable in terms of reducingcosts, size and parts needed in inventory. It also helps consolidate avery fragmented industry, into fewer parts and a more standardized powersupply footprint.

The logic uses the Primary Side Sensing to first find the correct CW,then finds within the CW the appropriate FW setting which matches theprimary side sensed voltage and current. Alternatively, if a “slowstart” is used, then the initial target can be fixed to the desiredoutput, for instance if it is a 5V×1 Amp device, then the initial targetwould be pre-selected at 5V×1 Amp. Then the system would move to the 5 voutput and current setting, but, within milliseconds, the actual sensemechanism on the primary side would begin to register information fromwhich the correct “window” would be selected. The CW are used so thatthe logic can segregate and reduce its initial selection. Otherwise, ifCW's aren't used, then the logic has to search all settings, rather thanjust the settings in a certain range. Thus, if the logic already knowsthe coarse window it is in, it only has to look at the fine tuningwithin that window, unless the sense input for sure tells the logic thatit has gone outside the coarse window, then it looks for a fine tunesetting within the second CW.

For this example of the invention, we are using a set of algorithms thatcalculate from 50 milliamps up to 4.5 amps, for example, as it could bemore amps. Also, for this example we are selected a 5V setting tomaintain. To exemplify the course window (CW) settings, one CW would bein the instance of plus or minus 50% of 1.5 amps is just coarse window,because it's very linear in that higher current range. However from 1,as we go down from 1.5 amps towards 50 milliamps the windows are verynarrow because the current is not very linear. However, each window hasa certain gain and offset. So it's an equation of a line that we arecreating by simulations within the Fine Windows in each CW which finetune the CW settings. Between 4.5 and 1.5 amps, it is an equation of aline so for that you would need a slope and an X intercept. So the slopeis already determined, or we can just call it a gain factor, it'sdetermined through simulations or on the bench, if you have the externaldiscrete parts and their losses are stored in memory so that they can becalculated into the gain settings so that an “overshoot” is accomplishedby producing extra current to compensation for the losses the modulewill experience in the Secondary. The same thing happens for correctionsfor temperature or other external variables, such as temperature, andwith the offset.

In this instance, when the system logic gets a primary side currentsense analog value, the output is digitized to an ADC, and then thatoutput is, the digital output is used, it determines which window we arein, so let's say we are in between 4.5 and 1.5 you're in window 1,right, so if you get 2 amps for example, and the corresponding digitaloutput from the current sensor will land us inside CW window 1 and thedigital engine will calculate using the slope and offset to calculate anew reference voltage in digital which will then find the FW and thenthat value will be applied and a loop is locked. This is how the loopworks. And then the number of windows is determined by the accuracy ofthe range, all the range if you just have one narrow range then we justcan loop it with one or two windows, for the 0.5 percent accuracy thereup to 49 CW windows needed to get the fine tuning necessary. So withthis configuration, you have 1664, total windows, which provides theresolution necessary for the type of accuracy desired.

As mentioned, the number of windows is determined by the accuracyrequirements, if the accuracy is looser then we need less windows, ifthe accuracy is tighter than 0.5 percent then we would need morewindows. It would vary according to the accuracy desired. In thisinstance we have set 64 total windows, with 49 CW for the 0.5 percentaccuracy.

In one embodiment, first, the soft-start mode is engaged and with thepre-selected value, which brings the system output close to 5 volts.Next, the current sensor, which is a switch cap amplifier, in oneembodiment of the invention, digitizes the output of the current whichis in terms of voltage. When the pulse width is high, the switch isclosed on the primary side, a sawtooth is generated and digitized by thereference and then digitized by the ADP. That signal is used as athreshold to select one of the 49 CW, that is to select only one out of49 CW.

Next, for example, the systems registers that it is in CW 1, based onthe current sensor output we calculate, this information is theninstantly used to determine next the offset and gain which are stored tocalculate within the CW references, which would be the FW with is therepresentation of what the reference voltage is or should be on thesecondary. That information is then used to create/generate a storedvalue for a PWM duty cycle modulated square wave to drive the system.

The voltage sensor is also used as a fine tuner to make sure that thereference voltage doesn't exceed above a certain window, which is fixedby the type and design of the system and its desired output voltage andcurrent, so that the PSR always stays within a certain range. In thisfashion there is coarse tuning, and fine tuning which can includeoffsets or gains for temperature, losses from the secondary discreteparts, and that type of additional calculation which is or may benecessary to truly have the PSR represent the exact conditions of theSecondary.

Thus, the FW fine tune's the current sensor and output measurement forfurther tuning from the referenced voltage from the digital andconverted back into analog for the driving the system. This is how thePWM is being implemented. The output of the reference, which is indigital format, is converted into analog for the 12 bit DAC, so withthat, it drives the PWM, which drives the comparator, the other input ofthe comparator is the sawtooth, and then output of the comparator is asquare wave duty cycle modulated, which drives the external FET whichdrives the forward convertor. The voltage sensor is based on the peakdetector, so it has a smaller rating than the current sensor. With thevoltage across the inductor of the magnetizing inductance of thetransformer. The voltage is peak detected, subtracted, and then that isused as during the reset time when the switch is off.

The CW slide algorithm is also implemented in digital. It's like therest of the PSR. This uses a counter and it starts up after the POR isreleased, and the PSI is enabled. In this embodiment, it uses a 2 bitcounter running at about 1.5 megahertz. It counts up to 3072 counts ininductor mode, which is ¾ths of the full count and then it takes about 2milliseconds to reach by this clock rate.

Then that when the POR of the soft-start engine releases and the voltageis set to attempt to reach 5 volts. That is then when the two-by-one MUXis implemented in digital. The output which is called Out INP which isseen on the right hand side, that's the output of the reference voltage.Of course, 2 milliseconds the clock and the counter is ramping up so thecounter is modeled as a, looks like a voltage source Vforward, from zeroto 3072, during that time the MUX is closed, so VDD2 is applied. (Thisis shown in the information attendant to the provisional patent filing).

That brings the voltage, starts bringing it up, gradually startsbringing it up, if the time is reduced, then there is the possibility ofringing being generated, so 2 millisecond is possible for bringing thesystem up. By bringing start up, and then an output calculation done inLT-Spice, so the middle curve, which is the red curve from the top, thethird one from the top, called V Out, that shows a soft start from zeroto 2 milliseconds, it starts up at close to zero and then it graduallystarts up, Vcounter Out is the output of the counter, or actually VPWMIDwhich is a bottom curve. It shows the counter counting up and then afterthat it says that it's closing at 3072 and the MUX switches to lessactual voltage come in and then the voltage starts to servo based onwhat the load currents are.

The power circuit 22 provides power controller integrated circuits(IC's) and corresponding integrated Modules provide a low-cost, highlyefficient means to convert the AC line voltage present at a typical homeor business electrical outlet to a reduced regulated DC voltage forconsumer electronic applications. Typical applications include, but arenot limited to charging systems for cell-phones, tablets or otherhandheld devices, USB power conversion, power supplies for consumer,medical and industrial devices, and many other possible uses. TheTronium Primary-Side Regulation Low-voltage (PSR-LV) IC when combinedwith a single Tronium High-Voltage (HV) Voltage Divider 32, provide acomplete system solution for US-only applications with AC line voltagesof 90V-132V. A second High-Voltage IC 32 containing a slave VoltageDivider can also be added to enable World-Wide applications for AC linevoltages of 90V-264V.

Some of the key features of the Tronium PSR-LV System are as follows:Primary-Side Regulation of Final Output Voltage using an advanced PSRwindowing algorithm; High-Voltage Switched-Capacitor Voltage Divider;Switch-Mode Buck Regulator Controller; Country Select LINE VoltageMonitor; Embedded 8051 Micro-processor for execution of power managementfirmware; 12-bit SAR ADC for high-speed sampling of current and voltage;Flash NVM for Code Storage; Ultra-Low Power Dissipation for Idle(Vampire) Mode of Operation; Optional Opto-Isolated Interface for AnalogSensing of the Output Voltage; and I2C Slave Interface Port forManufacturing Test.

The Tronium PSR-LV System combines the high-efficiency TroniumHigh-Voltage Voltage Divider IC with the Tronium Primary-SideRegulation-Low Voltage (PSR-LV) advanced power controller IC for outputvoltage regulation with high-efficiency and high accuracy. The twoTronium IC's provide a total solution for Primary-Side Regulation whichmonitors the voltage and current on the primary side of the transformerfor control of the secondary output voltage. As a result, the number ofexternal components is minimized providing a cost and area effectivesolution for power control. When no current is being drawn by the loadthe device will enter a low-current mode of operation to minimize thetraditional ‘vampire’ current required to stay awake.

The Tronium PSR-LV System (shown in FIGS. 47 and 49) is comprised of twointegrated circuits for control of the module Buck Switching Regulator(SWR) and Forward Converter. The Tronium Primary-Side RegulationLow-voltage (PSR-LV) IC integrates an ultra low-power controller for a5-Volt Cell-Phone or Laptop Charger Module. When combined with theTronium High-Voltage Voltage Divider, it provides a complete solutionfor US-only applications with AC line voltages of 108V-132V. A secondHigh-Voltage IC containing a slave Voltage Divider can also be added toenable World-Wide applications for AC line voltages of 90V-264V.Alternatively, the high voltage and low voltage circuits can co-exist inone chip which contains high voltage devices and low voltage devices.

Some of the key features of the Tronium PSR-LV IC are as follows:Primary-Side Regulation of Final Output Voltage using an advanced PSRwindowing algorithm; Embedded 8051 Micro-processor for execution ofpower management firmware; 12-bit SAR ADC for high-speed sampling ofcurrent and voltage; Flash NVM for Code Storage; Ultra-Low PowerDissipation for Idle (Vampire) Mode of Operation; Optional Opto-IsolatedInterface for Analog Sensing of the Output Voltage; and I2C SlaveInterface Port for Manufacturing Test.

The Tronium High-Voltage (HV) IC (shown in FIGS. 47 and 49) integrates aproprietary High-Voltage Switched-Capacitor Voltage Divider &Switch-mode Buck Regulator to maintain high-efficiency regardless of theload voltage or current. The Tronium HV IC is used to transfer powerfrom the rectified LINE voltage to the load as controlled by the PSR-LVLow-Voltage IC. The Tronium HV IC is comprised of the following majorcircuit blocks: High-Voltage Switched-Capacitor Voltage Divider;Switch-Mode Buck Regulator Controller; Country Select LINE VoltageMonitor; Bandgap for On-Chip Voltage and Current Generation; and 5V and10V LDO Regulators for supply of the PSR-LV IC Controller.

The Tronium PSR-LV System can be configured for the followingapplications:

US-Only Applications: The Tronium Primary-Side Regulation Low-voltage(PSR-LV) IC can be combined with the Tronium High-Voltage VoltageDivider to provide a complete solution for US-only applications with ACline voltages of 108V-132V and can exist in two chips, based on high orlow voltage circuits, or exist in one IC which has both high and lowvoltage devices and circuits. High voltage circuits are relativedepending on input and targeted output. With European and US type outletvoltages being considered, typically high voltage would be devices andcircuits which are designed to withstand in excess of 35-50 volts up to600 v, with low voltage circuits including circuits less than the 35-50v circuits and devices. In the case where both high and low voltagecircuits exist on the same IC they would be the TRONIUM HLV chip, whichdepending upon the option selected, may or may not include PRS, so thatit also can be a designated as a HLV-PSR chip.

This application can be seen in the diagram of FIG. 47 where theconnectivity between the two IC's is shown along with the external BuckSWR and Forward Converter. A single Tronium HV IC is used to provide thenecessary voltage division from the rectified LINE voltage to theprimary side of the transformer. The Tronium PSR-LV IC controls theprimary-side NMOS switch via Primary-Side Regulation to then efficientlytransfer power to the application load at VLOAD.

World-Wide Application: A second Tronium HV IC (shown in FIG. 49) isrequired for conversion of world-wide LINE voltages ranging from 90VAC-264 VAC. A diagram of this application is shown in FIG. 49 where theoutput of the first HV IC at CPOUT is used to drive the input of thesecond HV IC. This effectively provides two more stages of voltagedivision allowing for a wider range of input voltages. In this case thefirst HV IC is configured as the Master, while the second HV IC is theslave.

Master/Slave Configuration: The MSTR_SLV input of the Tronium HV ICallows each device to be configured separately for multipleapplications. Redundant circuits can then be disabled for additionalpower savings when needed.

Bandgap: The Bandgap reference voltage of the Tronium PSR-LV IC must betrimmed to obtain regulation accuracies of less than ±1.5%. As a result,a 4-bit register word can be stored in memory with the trim informationwhich can be obtained at either IC package or module test. High accuracyapplications can also be supported with the use of an external Bandgapreference generator. For this mode of operation, the internal Bandgap ofthe IC can be disabled via register control.

Oscillator: The Master Oscillator of the Tronium PSR-LV IC is designedfor high accuracy and will not require trim.

Calibration Methodology: 12-bit ADC. The 12-bit voltage and currentsense ADC of the Tronium PSR-LV IC will require a two point gain andoffset calibration to be performed on a periodic basis. The followingroutine will be used: 1) Apply VREFL and perform a conversion. Store theresult as dout_offset. 2) Apply VREFH and perform the conversion. Theresult is dout(refhi). 3) calculate the gain factor as gainfactor=(dout(refhi)−dout_offset)/4096; 4) For all subsequent conversionsthe result can be gain and offset corrected as follows:dout_corrected=(dout(actual)−dout(reflo)/gain_factor.

Temperature Calibration. Temperature calibration for the PSR can beperformed automatically in the background so that no manual calibrationis needed at the factory or in the field. The auto-calibration iscompleted in the following manner: 1) For a given load current at aknown temperature a specific PSR window is selected; 2) The pre-storedoffsets and gain are then used to calculate the specific output codewhich will provide 5.0V at 25 C (room temperature); and 3) As thetemperature changes from 25 C, for the same fixed load current, anotherset of gains and offsets are applied that will fine tune the output tomaintain regulation at 5.0V. Each window has a coarse tune (load currentdependence) and a fine tune (temperature sensor) dependence that is usedto maintain regulation.

An on-chip temperature sensor is provided on the Tronium PSR-LV IC toprovide the means for calibration. It will be characterized/simulatedover the temperature range of −40 C to 125 C in 20 degree increments,since it will be used to calculate the slope and offset for temperaturefine tuning. An off-chip temp sensor (RTD or delta VBE) could also beused instead of the on-chip version.

The Tronium Windowed PSR (Power Side Regulation) implements a low cost,high efficiency method of providing a regulated isolated secondaryvoltage source. Referring to FIGS. 47, 49, and 71, in one embodiment,the PSR 240 consists of an isolation transformer, reset capacitor,switching transistor and controller. The isolation transformer isoperated in the forward converter mode to minimize the amount of energythe core must store and therefore reduce the transformer's core size.The secondary voltage output is regulated using the transformer'sreflective inductor pulse which represents the power delivered to thesecondary load. The magnitude of the reflective inductor pulse increaseswith increasing load power. A programmable controller compensates forthe non-linear characteristic of the reflective inductor pulse and toprovide for more accurate regulation over temperature and componentvariations. The controller implements a multi-window method (up to 64windows) whereby each window represents a segment of the load current.Each window consists a programmable gain and offset component to enablefully characterizing any transformer configuration. The number ofwindows is dependent on the non-linear characteristics of thetransformer and the required accuracy of the secondary voltageregulation. The controller drives the gate of a switching MOSFET toimplement a PWM switcher. The PSR feedback signal is the reflectiveinductor pulse. This pulse must be reset (current through thetransformer's primary must be zero) for each PWM cycle for a properfeedback signal that represents the current secondary load condition.Correct selection of the reset capacitor's value ensures that thetransformer resets before the next PWM cycle. Referring to FIG. 77, thetiming events of the PWM cycle and the occurrence of the reflectiveinductor pulse of the primary side regulation circuit 240 areillustrated including plot 294 illustrating the MOSFET Gate Drive forswitching device 278 and plot 296 illustrating the reflective inductorpulse measured by voltage sensor 290. Referring to plot 294, Data Point(A) is the start of PWM cycle, MOSFET turned on, Data Point (B) is theMOSFET turned off, and Data Point (C) is the End of PWM cycle. Referringto plot 296, Data Point (D) is the occurrence of reflective inductorpulse and Data Point (E) is the transformer reset event.

Referring to FIGS. 72-73 and 80-85, in one embodiment, the regulationcontroller 284 includes a micro-controller based architecture for thePSR-LV a part of which can also be implemented in state machine analog.This architecture uses an external NVM for trim, code, and constantstorage.

The external or embedded micro-controller is responsible for the system(PSRLV and PSRHV) startup, operational modes, and overall PSR forwardconverter control loop management.

Digital/Analog Partition. The PSRLV encompasses the same features as theprevious Tronium ASIC low voltage elements. The Digital/Analog partitionis similar, with the exception that the PSR control loop will bepartitioned between the Digital and Analog Sub Systems. Themicro-controller is responsible for the system (PSR-LV and PSR-HV)start-up, operational modes, modes, and management of the PSR ForwardConverter Control Loop. FIG. 80 illustrates the top level state diagramand FIG. 81 illustrates the Analog/Digital partition for the PSR ControlLoop. The aqua colored blocks are implemented in the Analog Sub System.The PSRLV Digital Sub System for the PSR Control Loop is shown in theconceptual diagram shown in FIG. 82. The ADC Controller, the SleepCounter, Clock Generator, the Comparator Engine, and the PSR engine areimplemented in logic, with the remaining functions being implemented infirmware running on the micro-controller. Using fixed logic for theComparator Engine is necessary to support the 32 number of potentialcomparisons need to find the PSR Regulation Window Threshold (PRWT). Inpractice, most of the time the new PRWT should only be a few thresholdsapart from the old PRWT.

The PSR engine implements the required arithmetic calculations for thecontrol loop. The micro-controller has overall control of the PSR engineand has observability/controllability of intermediate calculations. Tomaintain resolution for the Pulse Width Modulation control signal,fwd_out, which goes to the external FET controlling current through thePrimary Transformer winding, the Digital Sub System provides a 12 bitwide DAC control word to the PWM DAC in the Analog Sub System.

Critical Firmware Execution Time Line. The critical Firmware Executionprocessing occurs while the PSR control loop is active. During this timethe PSR firmware will utilize the PSR Engine to update the PWM DAC pulsewidth control. As the PSR engine will be a fixed logic implementation ofthe arithmetic operations, the requirements on firmware are relaxed.Firmware will be able to enable the PSR Engine to run eitherindependently of the micro-controller, or under the micro-controller'sdirect supervision.

When the PSR Engine is under micro-controllers direct supervision, themicro-controller will be able to monitor and to interject data into thePSR Engine at key computational points. A PWM cycle is 100 Khz or higherand is derived from the micro-controller 20 Mhz clock. Referring to FIG.83, given the clock frequencies above it follows that there are 200micro-controller clock cycles per PWM cycle. Based on information fromthe micro-controller IP provider, on average the micro-controllerrequires 2.12 clocks per instruction. As currently envisioned, thefirmware running during a PWM Slot (cycle) will include a supervisoryprocess as well as the PSR algorithm management.

Micro-processor. The micro-processor was selected based on the ExecutionProcessing Time Line discussed in section 3.2 and the concept of havingfixed logic implementations for the arithmetic operations of the PSRcontrol loop. Two architectures are presented below.

1) An 8051 based micro-controller (8 bit) is considered as it will meetthe overall system control and PSR control loop management. Themicro-controller will also have the following peripherals: One 16 bitTimer (Timer 0); One Multiply/Division unit. (MDU); One Slave I2C port;Watchdog Timer; ISR Controller; and OCDS interface (On Chip DebugSystem).

2) An 80251 based micro-controller (16 bit) which also will meet theoverall system control and PSR control loop management, and additionallywill have added processing power to address future modifications to thePSR control loop algorithm. The micro-controller will also have thefollowing peripherals: One 16 bit Timer (Timer 0); One MultiplyAccumulate unit. (MAC); One Slave I2C port; Watchdog Timer; ISRController; OCDS interface (On Chip Debug System).

Digital Sub System. Based on the sections above, the architectures shownin FIG. 84 and FIG. 85 are being considered. A 8051 based architectureis depicted in FIG. 84 which is used as a reference as manymicroprocessor architectures may be used including ARM's. In oneembodiment, the micro-controller is configured as a Harvard architecturewhich means that there are two memory spaces, the code memory, and thedata memory. The two memory spaces are shared with a common externalmemory bus. With this architecture only code or data memory can beaccessed per micro-processor cycle. In addition, the micro-controller IPsupports 8 bit code and data busses.

A 80251 based architecture is depicted in FIG. 85. In one embodiment,this micro-controller is configured as a Harvard architecture whichmeans that there are two memory spaces, the code memory, and the datamemory. The two memory spaces have dedicated memory busses. With thisarchitecture both code and data memory can be accessed permicro-processor cycle. In addition, the micro-controller IP supports 32bit code and data busses. With this architecture, the micro-controllerprocessing power is enhanced, thereby supporting more computationallyintensive tasks than the 8051 based architecture.

For both architectures, or any other microprocessor used, the codememory space is comprised of SRAM or similar. The data memory space iscomprised of SRAM and a Register File. To support the multiplecomparisons required to implement the PSR control loop botharchitectures employ a hardware Comparator Engine to off-load thefirmware processing requirements. The Window Thresholds are stored inSRAM along with the gain and offset values for each window. Up to 64Windows will be supported. All thresholds values are 12 bit, the gainand offset. The Comparator Engine will compare the peak current sampleagainst the primary regulation window thresholds, PRWTs, which arestored in SRAM. Once the primary regulation window, PRW, has beenidentified, the Comparator Engine updates a register with an index intoSRAM that contains the Gain and Offset values for that PRW. Themicro-controller then accesses SRAM, using the index. The correspondingGain and Offset values located at that index, are then loaded into thePSR Engine to start the PSR control loop calculations. At startup themicro-controller moves the PRWTs, Gain, and Offset values into SRAM fromthe NVM.

Additionally a PSR Engine is used to off-load the computationalrequirements of the PSR algorithm from firmware. The PSR Engine will dothe required arithmetic calculations for the PSR control loop. The PSREngine is programmable in terms of gain coefficients. Themicro-controller may observe and control the integrator output, the12-bit counter used for fine tuning the integrator reference, and thedigitized ADC outputs for peak voltage and instantaneous current. Themicro-controller can also control the PSR update rate as well as whencalculations start.

The PSR Engine can be configured in an autonomous mode as well, suchthat the calculations are executed as soon as the Comparator Engine hascompleted without micro-controller intervention.

The ADC controller is dedicated hardware to support the low levelcontrol of the SAR ADC in the Analog Sub-System. Calibration iscontrolled via firmware. Once initiated, the ADC conversions for the PSRcontrol loop are under the control of the ADC controller. The ADCcontroller will support three independent channels for peak voltage,instantaneous current, and average current. There will be an on-boardtemp sensor for the IC and for the module, which will provide input forerror corrections as temps vary.

The Digital Sub-System implements power management features, including aSleep Mode, during which most of the Digital Sub-System and portionsrelated to regulation in the Analog Sub-System are disabled to reducecurrent consumption. The sleep counter is dedicated hardware to controlthe duration of the Sleep Mode. This allows for the micro-controller tobe disabled, via clock gating, during Sleep Mode.

Micro-Controller. Two Micro-controller are considered:

Option 1 the micro-controller will be an 8051 soft core. A possiblevendor would be CAST Inc. The IP also has soft IP peripherals that areprovided with the 8051 core. The IP with peripherals is ˜20 Kgates.

Option 2 the micro-controller will be an 8051 soft core. A possiblevendor would be CAST Inc. The IP also has soft IP peripherals that areprovided with the 8051 core. The IP with peripherals is ˜35 Kgates.

Non-Volatile Memory. For the external NVM architecture an off the shelfNVM memory would be used to hold the micro-controller firmware code. Onpower up, the bootloader would read the contents of the external NVM andwrite it to internal SRAM. After the firmware code is written to SRAM,the micro-controller would start running from SRAM, and execute theTronium PSRLV application code.

One possible NVM would be Atmel's AT28BV256 32 k×8 Parallel EEPROM.

The NVM will be mounted onto the ASIC die and both will be housed in thesame package.

SRAM. Depending on micro-controller the bus widths will be different.However, the total number of bytes is the same for both. The cost is thesame as well. The micro-controller executes from internal SRAM after thefirmware code has been retrieved from the external NVM and stored intothe internal SRAM. Again the Foundry provides various complied SRAMmemories as described above. In addition, piggybacked flash memory willbe used when necessary. The 128×32 SRAM IP is 0.06 mm². The 8K×32 SRAMIP is 1.618 mm².

Power and Size. The estimated Digital Sub-System dynamic current andsize is discussed below. For the 8051 based architecture: The estimateddynamic current is 0.52 ma, assuming a Sleep duty cycle of 50%. Theestimated Digital Sub-System area is 2.4 mm2 which includes thememories.

For the 80251 based architecture: The estimated dynamic current is 0.59ma, assuming a Sleep duty cycle of 50%. The estimated Digital Sub-Systemarea is 2.7 mm2 which includes the memories.

The implementation of the TRONIUM PSR can also be used for other powertypologies, such as flyback, buck, forward convertor, SEPIC, Push-Pull,and Cúk.

The PSRLV (which also includes the HLVPSR) Digital will implementOperational Modes, namely Startup, Normal, and Sleep Modes, with thesame functionality as on the prior Tronium ASIC. The Startup time frompower application to start of PSR is TBD. The Startup time from SleepMode (Soft Startup) to start of PSR is 1 ms typical. Firmware supportfor other modes which are entered/exited via I2C communication. Controlbit to force entry into sleep mode. When cleared ASIC will enter startupmode. Control bit to disable entry into sleep mode.

The PSRLV Digital will implement Alarm and Over Current functionality,similar to the previous Tronium ASIC. Alarm and Over Current Thresholdsare programmable and will be stored in NVM. This will allow forprogrammable support for multiple applications, including Cell Phone andLap Top applications.

The PSRLV Digital will implement Digital portions of the Primary SideRegulation (PSR) control loop. Architecture is micro-controller based.Peak Voltage, Peak Current, and Average Current are sourced from theAnalog Sub-System. The determination of the regulation Window, and thePSR control loop calculations, are done in fixed logic undermicro-controller supervision, and the actual PWM waveform generation isdone in the Analog Sub-System. The remaining supervisory functions willbe implemented in firmware running on the micro-controller. Configurablenumber of Window Thresholds. Up to 64. Dedicated logic for aconfigurable number of Window thresholds. All other thresholds will bederived from the Window threshold. The PWM DAC control word will bedithered to mitigate EMI effects.

The PSRLV Digital will implement a 12 Bit SAR ADC Controller similar tothe digital controller on the prior Tronium ASIC. Include support forsensing three independent channels, namely peak voltage, peak current,and average current sensing on the Primary Side Transformer. Calibrationfor Gain and Offset errors under firmware control for each channel. Autocorrection for Gain and Offset done in ADC Controller. 300 Khz SampleRate to support 100 Khz sample rate for each channel. Current andVoltage conversions synchronized to Rising and Falling edges of the PWMclock respectively.

The PSRLV will support Module Calibration. Internal Temp Sensorconfigurably used for compensation for the PSR control loop due toexternal component drift. Configurably used for over temperature faultcondition. External Temp Sensor configurably used for compensation forthe PSR control loop due to external component drift. Configurably usedfor over temperature fault condition. Register for gain settings. Storedin NVM. Registers for gain/offset calibration to PSR control loop.Stored in NVM. 8 bit for 0.05% FS adjustment, +/−6.35% FS total rangefor 5% module. 8 bit for 0.005% FS adjustment, +/−0.635% FS total rangefor 0.5% module.

The PSRLV Digital generates all required clocks for the Analog andDigital functions on the PSRLV ASIC. There is only one clock with afrequency 20 Mhz TBD. The PWM Master Clock will be 100 Khz. (Fixed).LFDIV clock used by Analog Subsystem as required. HFDIV Clock withprogrammable frequency as required. Sleep Counter Clock will be divideddown to provide programmable sleep duration in increments of 0.5 secondsup to 16 seconds.

The PSRLV supports configurability for multiple regulated outputvoltages. Charge Pump Voltage output configurability. Programmablenumber of Windows and Window Thresholds, gains, offsets.

The PSRLV Digital also implements an I²C slave or similar communicationsinterface. The I2C will also be used to support manufacturing test. TheI²C can be used to program the code space NVM after an initial codeload. I2C communication can occur at any time and can be from externalsources, like a cell phone, to turn on, turn off, or set a future timefor turn on/off of an electronic device powered by the TRONIUM ASIC. ThePSR control loop may be disabled when communication is active dependingon PSR mode.

The PSRLV supports internal or external NVM. The NVM will support TBDnumber of program cycles. The NVM will have a data retentionspecification of TBD number of years. The NVM can be programmed inSystem. The NVM implements security features to prohibit the reading ofNVM content by “unauthorized” persons. The NVM will implement securityfeatures to prevent inadvertent programming of the NVM. The NVM contentsare encrypted by the PSRLV such that reading the contents when removedfrom the module will return encrypted results. The NVM can be programmedover the I2C port or UART. The NVM can be programmed using the Debugport. The NVM content will be protected using EDAC. This will be managedby the NVM. The NVM is managed by firmware such that blocks withcorrectable errors will be relocated in the NVM. The PSRLV implements aboot loader. The boot loader will contain boot up information to supportthe micro-controller boot operation with an un-programmed NVM. Detectionof an un-programmed NVM will occur via reading a pre-determined NVMlocation and matching the contents against a correlated signature.

The PSRLV implements a debug system interface as provided by themicro-controller IP provider. The Debug port can be used to program theNVM. The Debug port can be disabled at manufacturing test.

The PSRLV will support Module Calibration: Internal Temp Sensorconfigurably is used for compensation for the PSR control loop due toexternal component drift. Configurably used for over temperature faultcondition. External Temp Sensor configurably used for compensation forthe PSR control loop due to external component drift. Configurably usedfor over temperature fault condition. Register for gain settings. Storedin NVM. Registers for gain/offset calibration to PSR control loop.Stored in NVM. 8 bit for 0.05% FS adjustment, +/−6.35% FS total rangefor 5% module. 8 bit for 0.005% FS adjustment, +/−0.635% FS total rangefor 0.5% module.

The PSRLV may either use trimming or may not require trimming on die. Inthe case of no trimming, internal Vref bandgap nominal less than +/−2%for 5% module accuracy. External Vref for module accuracy <5%, i.e.: use0.2% external reference for module accuracy of 0.5%. Configurable viaRegister. Stored in NVM.

The PSRLV also supports manufacturing test in the following manner: TheDigital will implement scan chains for the logic. The Digital willimplement (MBIST, Parallel external access, JTAG) testing for thememories, i.e., RAM and possible ROM for a micro-controller basedarchitecture. The Digital will implement test support functions tosupport analog testing and trimming using dedicated hardware.

The principle of Primary-Side Regulation relies on sensing theinstantaneous current and voltage seen by the primary winding of thetransformer. This information is then used to regulate the secondaryoutput voltage by Pulse-Width-Modulation (PWM) of the primary-sideMOSFET switch.

Referring to FIG. 74, the primary-side MOSFET switch is labeled as M1.The instantaneous voltage of the primary is sensed during the reset timeof the transformer, i.e., when the primary-side MOSFET is off; while theinstantaneous primary current is sensed when the MOSFET is turned on. Aresonant reset of the transformer is achieved with a 230 pF externalcapacitor (CR) connected between The PRIM_N pin and the ground pin. Thetolerance of the capacitor has been determined to be non-critical. TheMOSFET M1 has a 600 v allowed breakdown to allow operation at 100 KHz.

The external components required by the PSR circuit include MOSFETswitch, M1, Current Sense Resistor, Rcs, Current Sense Low-Pass Cap,Clp, capacitor, C1, Primary Side Reset Capacitor, C2, Inductor, L1,Diodes, D1, D2, and transformer, T1, and complete the Forward Converter.All external components, with the exception of the transformer, arecommon between the cell phone and the laptop platforms. The mode pin onthe Tronium IC selects one of these two platforms. There is some trimcapability which can be set digitally via on-chip registers.

Primary-Side Voltage Feedback Loop. The voltage feedback loop iscomprised of a peak detector and an instrumentation amplifier. Voltagefeedback information is obtained by sensing the differential voltageacross the primary-side terminals of the transformer. The positiveprimary voltage is sensed at the output of the Charge Pump at pin CPOUTand the negative primary voltage on the drain of MOSFET M1 at pinPRIM_N. A peak detector is provided to detect the peak voltage on pinPRIM_N.

The two voltages (PRIM_N & CPOUT) are subtracted and amplified by aninstrumentation amplifier whose gain is set by the mode pin whichdefines either the cell phone or laptop mode of operation. Since thetransformer turns ratio and the secondary voltage are different forthese two modes of operation, two different gains are supported. Theyare implemented as ratio of the feedback resistor to the input resistorin the instrumentation amplifier.

A window comparator compares the output of the instrumentation amplifierwith two thresholds (VTH & VTL). A logic Decoder derives an up and downsignal which then drives an 8-bit R2R DAC. This DAC adjusts thereference voltage in the integrator to achieve the required outputvoltage regulation from 4.5 Amps to 300 mA.

Primary-Side Current Feedback Loop. The current feedback loop comparesthe low-pass filtered voltage on the RCSP pin using a switched-capacitorinstrumentation amplifier with a digitally programmable gain. The gainaccounts for a range of parasitic resistances which can be seen on theSecondary. These resistances are comprised of a) the diode seriesresistance for diodes D1 and D2; b) the winding resistance of thesecondary side of the transformer; c) the interconnect resistance of thePCB and IC metal traces; and d) the series resistance of the 22 μHinductor. Since the maximum load current can be as high as 4.5 A, theaccumulated IR drops can be significant. Furthermore, the load currentcan vary from 50 mA to 4.5 A producing an output voltage droop which isload dependent. As a result, this could cause the loop to fail to meetthe +/−5% output regulation specification for this application. Theswitched-capacitor amplifier scales the incoming low pass filteredvoltage, converts it to an estimate of the secondary side current,scales it with a reference voltage and then drives a continuous timedifferential amplifier for further processing by the low passintegrator.

Primary Side Regulation—Analog Alternative Analog Version.

An alternative to the flash Primary Side Regulation, which doesn't useflash, because the flash which operates at three megahertz for a fivebit and requires 32 comparators and a resistor running at 3 megahertz,it's about a couple hundred micro amps current. This permits primaryside sensing of the secondary voltage and current, which omits the optocoupler and a number of parts. Another embodiment is a counter basedapproach, which can be selected as an alternative.

The system could also use the flash Primary Side Sensing, as mentionedabove, using the PID loop and doing remote sensing, one can have a 2 by1 staged voltage reduction circuit. The system can select that secondchannel and bring the feedback in and then disable the digital part, orthe digital controller.

This Primary Side Sensing approach provides (1) Improved Primary-SideRemote Sense Architecture, (2) Reduced Current Consumption byEliminating Flash ADC's, (3) Improved Startup Mode, (4) BetterRegulation Accuracy not Limited by ADC Resolution, (5) Analog Feedbackallows Opto-Isolator Feedback as Backup or Alternative.

This Primary Side Sensing and Regulation is based upon Secondary OutputVoltage where the expression can be calculated as shown in thecalculation below:

$V_{OUT} = {\left( {V_{PRIM}\frac{- V}{N\mspace{14mu}{PRIM}\mspace{14mu} P}} \right) \times \frac{tRST}{tSW} \times \frac{2}{\pi \cdot \left( {N_{P}/N_{S}} \right)}}$

The analysis behind the regulation so this output V_(OUT) is equal to,this V_(OUT) is in the secondary site, so V_(OUT) can be calculate whereV_(OUT) is a function of only the primary site parameter so this, allthe parameters on the right hand side of the equation, above. Thatinformation about the secondary side is available on the primary side,and N_(P) over N_(S) is the turns ratio of the transformer, so that is aknown and varies between different voltage output settings under the“dial-a-voltage” idea. Thus, the calculation works whether it is a cellphone or a laptop or a tablet or the like, and one can digitally selectit. The above equation has three parts. There's a first part which isthat V Primary Side Voltage, N minus V Prim P, that's the first part ofit is that time ratio and the second part is the time ra, and then thethird part that constant factor relating to the transformer ratio. Sothe constant factor is just a gain setting, where different gainsettings, digitally programmable so between laptop and cell phone onecan switch between them and select the correct regulation loop canadjust.

The TRST set and TSW is fixed, which is the switching time, which is 10microseconds in the preferred embodiment. So that's the thing for bothlaptop and cell phone. TRST set is the one that gets calculated by thedigital, there's a time to digital converter which converts time into adigital value and that is used to regulate. And V Prim N minus V Prim Pis the differential voltage across the inductor, across the magnetizinginductor on the primary site. So there's just a PG programmable gainamplifier which will calculate. In the equation above, the 2 is aprogrammable number, so for a cell phone 2 over Pi and NP over NS is theturns ration which in one case is 11/1 for the cell phone and 3/1 forthe laptop. So this is a programmable and adjustable sensing andregulation scheme. For instance, there is one calculation for the onenumber for the laptop and one number for the cell phone charger. Highresolution DAC's help. In the equation above, NP over NS is atransformer ratio, so NP over NS is the turns ratio. So it's 11:1 forthe cell phone and 3:2 for the laptop.

Referring to FIG. 74, in one embodiment, the primary side regulationcircuit 240 may include an analog Primary Side Sensing/Regulation Scheme(APSSR) which includes a different amplifier, which measures the energypeak, which also takes a peak detector, which measures the peak of thewave. When the transformer MOSFET switch is closed, there is noinformation on voltage or current, which is a problem that didn't existin the Digital Primary Side Sensing/Regulation Scheme (DPSSR) that'swhen the problem, the challenge here is that unlike before, where theinformation was always available, it didn't matter that the switcheswere closed or open, the output voltage can be momentarily calculated orreflected to back towards on the primary side during the off time of theswitch, which is during the reset phase. During the reset phase, thevoltage on the primary side goes up and so that basically thetransformer is demagnetizing so the primary side inductance, so the peakdetector catches the top part of the peak and then one would take thatand CP out, which is set by the Buck and the Switch Cap VoltageDividers, and the different amplifier measures that difference and thenone would go into PGA which implements the gain, the constant factor(i.e., the 2 over Pi NP over NS part of the equation above) so that'sthe programmable part of the PGA. The modifier is inside, is showninside the PGA, the left hand side corner block which is the PGA, inFIG. 74.

A Digital to Analog Convertor (DAC) is modified to, or increased inresolution to be able to accommodate more settings. The differenceamplifier includes an alternate path which is called the windowcomparator and then the time to work its convertor. So one wouldcalculate the reset time that the pulse took so you want to measure thevoltage, the differential voltage, which is the Y axis, but one wouldalso want to measure the time that it took for the inductance to bereset. Reset means that the differential voltage is zero. Thedifferential voltage starts at zero because the MOSFET (that drives thetransformer) switch is, initially when the switch is closed, youbasically place 110 volts by 0 volts across the inductance, themagnetizing inductance on the primary side and when you open the switch,there is an additional voltage that is a different voltage that isgenerated across the inductance and that's a function of the loadcurrent, how much load is being pulled from the secondary side.

So the time of collapse has to be measured and that's where this iscalculated. Thus, one may take a look at the window comparator and thetime to voltage converter is like a crude ADC. So there's a comparator,the window comparator, and then a counter, and then the counter is resetand then one would start the counter and the output of the countermimics and has a digital value which reflects the reset time. It islinearly related to the reset time. So the reset time cannot be morethan the maximum reset time that you can ever have is 10 microseconds,because that the time, switching time, or the time slot, so that ratiothat if you look at the back of the equation, above, the V_(TRST) or theV_(TSW), now you would calculate the reset time by this counter, by thiswindow comparator/time to voltage peak counter, then one would get onenumber and then you already know that V_(TSW) is a full scale of thecounter so that, so one gets two sets of different numbers, another PGA,which is basically shown as one PGA, but you can have another PGA whichbasically does the division, basically calculates the ratio.

Thus, first you have converted the time into digital number; and thenthat digital number drives a DAC, so the system is going from Digital toAnalog. Then you take the analog voltage, a ratio of analog voltageswhich is a function of middle part of the equation. The result is thatyou convert the timing, time ratio into a voltage ratio and then it iscompared with the already known voltage, differential voltage that hasbeen measured through the MOSFET peak detector across the magnetizinginductors are already known and ready to be used, then you go into a PGAand the PGA will basically multiply it and divide it depending on howit's configured and then basically that represents the V_(OUT) actual onthe secondary. So at the output of the PGA, you will see V_(OUT) actualof the current and voltage which exists on the secondary side, what isthe actual V_(OUT). And then I already know what my V_(OUT) desired is,which is 5 volts, so then the integrator will take the difference thenthere is 5 volts on one side of the integrator, because it is known thatthis is a 5 volt system, and then the actual voltage on the other sideof the integrator, the difference is your error, and then the error getsintegrated, and then digitized by the comparator, then this informationis no different than the original PID loop in the DPSSR.

Thus, the integrator drives the comparator, which basically takes theheader and works that into a pulse width, the pulse is of differentpulse width, and that drives the transformer MOSFET switch (the gateswitch) and then there's a clock generator just like before which isconstantly running at 100 kilohertz. So that's, and then so in this caseI, that's basically how to loop works or how the server works.

There's two different quantities that are dynamically changing, one isthe magnetizing voltage, it's the V set time, depending on the loadcurrent, and the other is the time for it to demagnetize, or the timefor reset.

There are no off die parts, it's all on chip, it's no different than theflash ADC as described above, instead of the window comparator and thetime to hold this converter had a flash ADC and then the integrator andthe PGA, they were also digitally implemented so the flash ADC would,had a digital integrator so that would take the digital differencebetween the actual and the desired voltage.

Thus, in the DPSSR one would need two flash ADC's, one for the feeddetector path and one for the time-to-voltage converter path. In theinstance of the DPSSR, one would therefore need two flash ADC's and thenall the digital arithmetic, logic log to do the math, to calculate theactual V_(OUT) desired and the digital format but in the instantinvention, shown here as the APSSR, that that is analog, it's low power,and does not require external components, and it's also compatible withthe PID, so that you can turn it off and use the opto isolation option,which provides an alternative and enhanced flexibility.

As shown in FIG. 74, on the secondary one embodiment of the circuit hadtransistors and the other has diodes. Because of the IR drop withdiodes, in this version of the invention, MOSFETS are used. With thatsaid, one has to manage is the IR drop on the secondary side so that's,so we took the diodes out because of the V forward voltage loss that theAPSSR system is not able to calculate. Therefore, using transistors(MOSFETS) provides a much lower IR drop and so basically the IR drop ismainly limited by the inductor, ESR that transformer turns ratio ESR andthen, which in this instance is about 26 milliohms and then the dropacross the M2 transistor called M2 on the return side. Which is prettysmall and it's not, it's like 10 or 20 millivolts, so the biggest, thebiggest error is the IR drop of the ESR basically that, because the Vout equation, if you look at that equation, that does not have that anddoes not have that information about losses from the secondary side.Before we were sensing the secondary site directly so all that IR dropwas taken into account and the servo would servo it.

The system is load dependent, and it's, as the load changes on thesecondary side, you get different IR losses, which are not calculated inthe above equation. In addition, there's a droop in the system as itoperates. Thus, voltage V out will go down, will start to droop as loadcurrent goes up.

This can be resolved in several ways. One was to compensate in the APSSRis to just to compensate it without having another servo loop. In thisfashion, one would compensate for the secondary side losses (IR drops)so that we are always at the mid-point. Thus, you would compensate itfor like the 1 amp instead of 4 amp, between 4 amp and 50 milliamps, sowe are around 1 amp P, set that droop so that it's at one amp, it's atmidpoint, so that the error is pretty much balanced at light loads andat maximum loads.

However, the information exists on the primary side. In a morecomplicated approach the information is obtained from the is there onthe primary side, the 0.1 of RCS resistor shown below and that has thepeak currents on the primary side and then so you can have another servoloop which can calculate the average current on the secondary side basedon the turns ratio and then from there you can additionally determine anIR drop on the secondary side equation of the line and then basicallycompensate it so you basically adjust the desired voltage a little bithigher based on the current. In other words, you basically pre-distortthe voltage going on the primary side to the secondary side, so thatwhen it goes to the secondary side the IR drop is removed from theequation and is cancelled out by the increase of voltage on the primaryside. Then the droop goes away and the V_(OUT) stays flat and V_(OUT)stays constant across different IR drop loads.

The IR drops on the secondary are thus pre-calculated into the amount ofvoltage and/or current sent through the transformer, so that when thevoltage and/or current reaches the secondary side, the IR losses fromthe transformer and devices on the secondary are already calculated in,and thus, cancelled out in the final throughput current to the externaldevice output.

In addition you can have another DACs where temperature is taken intoaccount, such that as the voltage or current increases, there would bean assumed or measured temperature increase, for which an additionaladjustment would be made to compensate for the IR losses at higher heatof the devises on the secondary side.

It's just the transistor N2 and L1. ESR L1 and ESR of that's specific tothat transformer. There's a secondary winding, which in thisconfiguration is 30 milliohms in L1 (maximum) it's 30 milliohms ofresistance, and then there's also 13 milliohms in L1 and the maximumthen about 10 or 20 millivolts across N2.

Because there can be a spike when the buck is energized while the SwitchCapacitor Voltage Divider (Reverse Charge Pump) is in operation, stepsneed to be taken to reduce and eliminate the spike within the TRONIUMcircuit.

Thus to eliminate the interaction between the loops it is necessary toonly operate the Reverse Charge Pump in the fractional mode when theBuck Regulator is disabled. Therefore, when the Buck Regulator turns on(above 50 mA into the transformer primary is one setting) the ReverseCharge Pump is set to go into the regulated mode. This has the effect ofminimizing the interaction between the Buck Regulator and the ReverseCharge Pump and provides the highest efficiency.

In this instance, the Tronium system is designed to run at the VLINElevel of 260 VDC. Additionally, the current is stepped from 1 mA to 200mA. Note that the Buck Regulator is set to regulate an output level of110 VDC, which is optimum for energy efficiency. This is also tofacilitate the voltage sag from the 100 μF cap when the input is at 127VDC. The Reverse Charge Pump comes up first at a fractional value of 0.5and outputs 130 Volts.

The Buck then turns on after the current step and the Reverse ChargePump is placed into the regulate mode at 130 Volts. The Reverse ChargePump is essentially turned OFF because of the Buck Regulator's lowerRDS-ON switch resistance. As the current step occurs, the charge fromthe 7.5 μF hold capacitor is bled off to 110 Volts at which time theBuck then starts to supply current. Note that the output voltage showsno abrupt behavior. The current is stepped down and the Buck turns off.The Reverse Charge Pump then brings the output voltage to its fractionalvalue of 130 Volts.

The Charge Pump 1 KHz clock (the behavioral digital is running at thedefault VHIGH of 1 volt) and the 5 V drive to the Buck switch running at100 KHz. The middle trace shows the 80 mA current step. In addition, theReverse Charge Pump must be permitted to settle. The Buck pulls a lot ofcurrent to increase the output voltage, shuts off momentarily and beginsto regulate once the voltage spike has fallen to 110 VDC. The current isstepped back down and the Reverse Charge Pump comes on once again fornormal operation.

Referring to FIG. 48, in one embodiment, the Switch Capacitor VoltageDivider (“SC”) is functionality implemented with inexpensive and readilyavailable components, with a different Start-up method, differentdiscrete components and μC, different Clock generation, external crystal(XTAL) and/or a microcontroller, μC, DCO, a Clock adjustment through μCimplementation, with final regulation through external high efficiencyflyback converter, instead of a forward convertor. This Modular approachallows for quick prototyping and agile development of core alreadyexplained inventions.

In and alternative of the invention, the SC topology can be used with aSEPIC, BUCK, FLYBACK, CúK, PUSH/PULL or other topologies as a hybridcircuit.

Here, the Clock frequency regulation is accomplished with μC (withon-board ADC) which measures the Switch Capacitor DC-DC converter outputvoltage with a suitable conditioning circuit, e.g a resistive dividerand μC regulates and generates the clock frequency and measures the SCDC-DC converter output voltage at the start-up without load, and adjuststhe clock frequency to achieve maximum efficiency across loads,

To begin with, the Main voltage selection, at startup, is analyzed bythe μC which measures the open circuit voltage of the SC DC-DC converterand then the μC determines if the main voltage is 220V or 110V. Thus, atStartup the SC DC-DC is converter not active.

A low-current (few mA) 5V auxiliary supply voltage is derived directlyfrom the rectified main voltage, e.g., with a resistive divider witheventually an LDO, and during startup μC is powered by Startup circuit.

The auxiliary output voltage is used for supplying the clock generatorand for bootstrapping the SC DC-DC converter. This auxiliary supplyvoltage (Startup circuit) is switched off by the microcontroller whenstartup is complete

When the SC DC-DC converter is settled, then the flyback converter isturned on. When the output voltage of the flyback converter is ready,then the auxiliary supply voltage is switched off and the Flybackconverter supplies the μC and then can power the current needed.

In another aspect of the invention, under the hybrid SC/BUCK designexplained above and in prior figures, the System automatically selectsthe proper gain setting for the Reverse Charge Pump Voltage Divider bymeasuring the incoming LINE voltage.

Two comparators monitor the scaled LINE voltage to determine the correctgain setting. This block can either always be on, so it uses lowcurrent, so as not to affect the vampire current or turned off andcontrolled by a state machine or microprocessor which is powered, sothat it is off during vampire loads or no loads.

The Buck Regulator (as shown in FIG. 66) regulates the intermediatevoltage on the Primary-Side of the Transformer regulates CPOUT to 110V.Turns on for load currents >50 mA, then the intelligence uses anexternal PMOS switch, inductor, diode, and two capacitors.

The Proportional-to-Integral and Differential (PID) Control Loop isshown with on-chip loop components. Also shown is the High-Voltage PMOSGate Driver, 20V LDO Regulator for PMOS Gate Drivers.

This topology uses a 12 BIT SAR ADC which incorporates a 6b+6b SegmentedArchitecture, with Auto-zeroed Multi-Stage Comparator, with Periodic TwoPoint Offset and Gain Calibration, and Single Channel ADC Conversion(Current Sensor).

The architecture also includes a Low Speed Current Sensor which has aDedicated Current Sense for Primary-Side Transformer Current as set outabove, with a Selectable Gain for Cell-Phone or Laptop Charger Modes anda Dedicated input to 12-bit ADC.

The Key Features of the Current Sensor design is Switched CapacitorProgrammable Gain Amplifier with offset cancellation. Also, due todifferent output voltages two different gains are supported for thelaptop mode and cell phone mode, and other gain setting are supportedfor various voltages/currents. The time constant is ˜2 ms (1 tau), with12b ADC calibration includes the Current Sensor channel and 0.1 vcalibration voltage→Full Scale ADC Output for Laptop Mode, with 0.025calibration voltage→Full Scale ADC Output for Cell Phone ModeVout=Vin*Gain+Vcm, where Vout is the output of the current sensor goinginto the 12b SAR ADC Vin is the input from the RC low pass filterVcm=1.25 v. For example the settings would be Gain=80 (cell phone), 20(Laptop) (digitally selectable). The Error Budget as set out above, forthe APSSR is: IR Drop of the ESR of the inductor+TransistorsVds*2+Transformer winding·12 mΩ*4.2 A+5 mΩ*2*4.2 A+13 mΩ*4.2 A→(0.1466v/2+5 v)→˜+/−1.5% accuracy taken up by the ESR.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Other aspects and features ofthe invention can be obtained from a study of the drawings, thedisclosure, and the appended claims. The invention may be practicedotherwise than as specifically described within the scope of theappended claims. It should also be noted, that the steps and/orfunctions listed within the appended claims, notwithstanding the orderof which steps and/or functions are listed therein, are not limited toany specific order of operation.

A controller, computing device, or computer, such as described herein,includes at least one or more processors or processing units and asystem memory. The controller typically also includes at least some formof computer readable media. By way of example and not limitation,computer readable media may include computer storage media andcommunication media. Computer storage media may include volatile andnonvolatile, removable and non-removable media implemented in any methodor technology that enables storage of information, such as computerreadable instructions, data structures, program modules, or other data.Communication media typically embody computer readable instructions,data structures, program modules, or other data in a modulated datasignal such as a carrier wave or other transport mechanism and includeany information delivery media. Those skilled in the art should befamiliar with the modulated data signal, which has one or more of itscharacteristics set or changed in such a manner as to encode informationin the signal. Combinations of any of the above are also included withinthe scope of computer readable media.

The order of execution or performance of the operations in theembodiments of the invention illustrated and described herein is notessential, unless otherwise specified. That is, the operations describedherein may be performed in any order, unless otherwise specified, andembodiments of the invention may include additional or fewer operationsthan those disclosed herein. For example, it is contemplated thatexecuting or performing a particular operation before, contemporaneouslywith, or after another operation is within the scope of aspects of theinvention.

In some embodiments, a processor, as described herein, includes anyprogrammable system including systems and microcontrollers, reducedinstruction set circuits (RISC), application specific integratedcircuits (ASIC), programmable logic circuits (PLC), and any othercircuit or processor capable of executing the functions describedherein. The above examples are exemplary only, and thus are not intendedto limit in any way the definition and/or meaning of the term processor.

In some embodiments, a memory device includes a computer readablemedium, such as, without limitation, random access memory (RAM),read-only memory (ROM), erasable programmable read-only memory (EPROM),flash memory, a hard disk drive, a solid state drive, a diskette, aflash drive, a compact disc, a digital video disc, and/or any suitabledevice that enables a processor to store, retrieve, and/or executeinstructions and/or data.

In some embodiments, a database, as described herein, includes anycollection of data including hierarchical databases, relationaldatabases, flat file databases, object-relational databases, objectoriented databases, and any other structured collection of records ordata that is stored in a computer system. The above examples areexemplary only, and thus are not intended to limit in any way thedefinition and/or meaning of the term database. Examples of databasesinclude, but are not limited to only including, Oracle® Database, MySQL,IBM® DB2, Microsoft® SQL Server, Sybase®, and PostgreSQL. However, anydatabase may be used that enables the systems and methods describedherein. (Oracle is a registered trademark of Oracle Corporation, RedwoodShores, Calif.; IBM is a registered trademark of International BusinessMachines Corporation, Armonk, N.Y.; Microsoft is a registered trademarkof Microsoft Corporation, Redmond, Wash.; and Sybase is a registeredtrademark of Sybase, Dublin, Calif.)

Although specific features of various embodiments of the invention maybe shown in some drawings and not in others, this is for convenienceonly. In accordance with the principles of the invention, any feature ofa drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

What is claimed is:
 1. An electrical circuit for providing electricalpower for use in powering electronic devices, comprising: an inputterminal configured to receive an input power signal; an output terminalconfigured to provide an output power signal; a plurality of voltagereduction circuit cells coupled between the input terminal and theoutput terminal the plurality of voltage reduction circuit cellsconfigured to operate in a plurality of operational modes to deliver theoutput power signal having a voltage level that is less than the voltagelevel of the input power signal, each voltage reduction circuit cellincluding: a first flyback capacitor; a second flyback capacitor; a holdcapacitor; and a switching circuit including a plurality of switchingdevices coupled to the first and the second flyback capacitors, theplurality of switching devices including a first switching device forcoupling a negative plate of the first flyback capacitor to ground and asecond switching device for coupling a negative plate of the secondflyback capacitor to ground, at least one of the plurality of switchingdevices coupled between the hold capacitor and the first and the secondflyback capacitors; a forward converter coupled to the plurality ofvoltage reduction circuit cells for receiving an intermediate powersignal from the plurality of voltage reduction circuit cells anddelivering the output power signal to the output terminal, the forwardconverter including a transformer and a transformer regulation switchingdevice coupled to a bottom end of a primary side winding of thetransformer and to ground; an input voltage sensing circuit configuredto sense a voltage level of the input power signal; a current sensecircuit configure to sense a current level of the primary side windingof the transformer; and a controller configured to: determine a gainsetting for each of the plurality of voltage reduction circuit cells asa function of the sensed voltage level of the input power signal andoperate each voltage reduction circuit cells at the correspondingdetermined gain setting; and operate the transformer regulationswitching device to regulate the transformer as a function of the sensedcurrent level of the primary side winding of the transformer to deliverthe output power signal at the predefined output signal voltage level.2. An electrical circuit in accordance with claim 1, the plurality ofvoltage reduction circuit cells including a first voltage reductioncircuit cell and a second voltage reduction circuit cell coupledtogether in series between the input terminal and the output terminal,the first voltage reduction circuit cell being coupled to the inputterminal, the second voltage reduction circuit cell being coupled to theoutput terminal, the first voltage reduction circuit cell beingregulated at a first capacitive gain setting, the second voltagereduction circuit cell being regulated at a second capacitive gainsetting that is different from the first capacitive gain setting.
 3. Anelectrical circuit in accordance with claim 2, wherein the firstcapacitive gain setting includes a voltage division ratio that is lessthan a voltage division ratio of the second capacitive gain setting. 4.An electrical circuit in accordance with claim 1, the plurality ofvoltage reduction circuit cells including a first voltage reductioncircuit cell and a second voltage reduction circuit cell coupledtogether in series between the input terminal and the output terminal,the first voltage reduction circuit cell being coupled to the inputterminal, the second voltage reduction circuit cell being coupled to theoutput terminal, the first voltage reduction circuit cell includingswitching devices having a voltage rating that is larger than a voltagerating of the switching devices of the second voltage reduction circuitcell.
 5. An electrical circuit in accordance with claim 1, wherein thecontroller is configured to: select a switching device in each of thevoltage reduction circuit cells; and generate and deliver a controlsignal to each of the voltage reduction circuit cells as a function ofthe corresponding gain settings to operate each voltage reductioncircuit cells at the corresponding determined gain setting includingoperating the selected switching devices in an off-position during eachof the plurality of operational modes.
 6. An electrical circuit inaccordance with claim 5, wherein the plurality of voltage reductioncircuit cells includes a regulated voltage reduction circuit cellcoupled to the output terminal for delivering the output power signal tothe output terminal, the controller configured to: sense a voltage levelof the output power signal; and regulate the control signal delivered tothe regulated voltage reduction circuit cell as a function of thevoltage level of the output power signal, the controller configured toadjust a duty cycle of the control signal to adjust the gain setting ofthe regulated voltage reduction cell to maintain the voltage level ofthe output power signal at the predefined output signal voltage leveland a desired output current level.
 7. An electrical circuit inaccordance with claim 6, the controller configured to: determine avoltage level of the input power signal; determine the predefined outputsignal voltage level and the desired output current level; determine arequired number of voltage reduction circuit cells to deliver the outputpower signal at a voltage level approximately equal to the predefinedoutput signal voltage level as a function of the voltage level of theinput power signal and the desired output current level; select an inputvoltage reduction circuit cell of the plurality of voltage reductioncircuit cells for receiving the input power signal, the input voltagereduction circuit cell being selected as a function of the determinedrequired number of voltage reduction circuit cells; determine a gainsetting of each of the required number of voltage reduction circuitcells as a function of the predefined output signal voltage level; andgenerate and deliver control signals to each of the required number ofvoltage reduction circuit cells as a function of the corresponding gainsettings.
 8. An electrical circuit in accordance with claim 7, thecontroller configured to: select at least one bypass voltage reductioncircuit cell of the plurality of voltage reduction circuit cells as afunction of the required number of voltage reduction circuit cells; andoperate the at least one bypass voltage reduction circuit cell todeliver the input power signal to the input voltage reduction circuitcell including operating the switching circuit of the at least onebypass voltage reduction circuit cell in a bypass mode to couple thepositive plate and the negative plate of the first capacitor to each ofa cell input terminal and a cell output terminal of the at least onebypass voltage reduction circuit cell to short the first capacitor andto disconnect the second capacitor from each of the cell input terminal,the cell output terminal, and the first capacitor, wherein the sourceand drain of the switching devices associated with the first capacitorare shorted in parallel.
 9. An electrical circuit in accordance withclaim 5, wherein at least one of the plurality of switching devicesincludes: an N-channel MOSFET; a dickson charge pump coupled to a sourceof the N-channel MOSFET and configured to generate a high voltage chargepump signal having a voltage level that is greater than the voltagelevel at the source of the N-Channel MOSFET; and a level shifter coupledto the dickson charge pump and the N-channel MOSFET, the level shifterconfigured to receive the high voltage charge pump signal and a controlsignal and transmit a high voltage control signal to a gate of theN-channel MOSFET.
 10. An electrical circuit in accordance with claim 1,the controller configured to: select an output voltage reduction circuitcell from the plurality of voltage reduction circuit cells as a functionof the predefined output signal voltage level; operate the selectedoutput voltage reduction circuit cell to couple the output voltagereduction circuit cell to the forward convert to deliver theintermediate power signal from the output voltage reduction circuit cellto the forward converter; and regulate the forward converter to deliverthe output power signal to the output terminal.
 11. An electricalcircuit in accordance with claim 1, the plurality of voltage reductioncircuit cells including a first set of voltage reduction circuit cellsand a second set of voltage reduction circuit cells coupled between thefirst set of voltage reduction circuit cells and the output terminal,the first set of voltage reduction circuit cells being coupled togetherin series, the second set of voltage reduction circuit cells beingcoupled together in parallel.
 12. An electrical circuit in accordancewith claim 1, further comprising: a buck regulator circuit coupledbetween the input terminal and the output terminal, the forwardconverter coupled to the buck regulator circuit, the plurality ofvoltage reduction circuit cells, and the output terminal for deliveringpower signals from the buck regulator and the plurality of voltagereduction circuit cells to the output terminal.
 13. An electricalcircuit in accordance with claim 1, at least one of the plurality ofvoltage reduction circuit cells including an inductor and a diodecoupled to the switching circuit and the hold capacitor to facilitateoperating the at least one voltage reduction circuit cell as a buckregulator circuit.
 14. A method of operating an electrical circuit forpowering electronic devices, the electrical circuit including an inputterminal configured to receive an input power signal, an output terminalconfigured to provide an output power signal, a plurality of voltagereduction circuit cells coupled between the input terminal and theoutput terminal, a forward converter coupled to the plurality of voltagereduction circuit cells for receiving an intermediate power signal fromthe plurality of voltage reduction circuit cells and delivering theoutput power signal to the output terminal, and a controller, each ofthe voltage reduction circuit cells including a first flyback capacitor,a second flyback capacitor, a hold capacitor, and a switching circuitincluding a plurality of switching devices coupled to the first and thesecond flyback capacitors, the plurality of switching devices includinga first switching device for coupling a negative plate of the firstflyback capacitor to ground and a second switching device for coupling anegative plate of the second flyback capacitor to ground, at least oneof the plurality of switching devices coupled between the hold capacitorand the first and the second flyback capacitors, the method includingthe controller performing the steps of: determining a voltage level ofthe input power signal; determining a voltage level of the output powersignal; determining a gain setting for each of the plurality of voltagereduction circuit cells as a function of the voltage level of the inputpower signal and the voltage level of the output power signal; selectinga switching device in each of the voltage reduction circuit cells;regulating the plurality of voltage reduction circuit cells in aplurality of operational modes at the corresponding gain setting todeliver the intermediate power signal to the forward converter,including operating the selected switching devices in an off-positionduring each of the plurality of operational modes, and regulating theforward converter to deliver the output power signal at thecorresponding determined voltage level, wherein the forward converterincludes a transformer and a transformer regulation switching devicecoupled to a bottom end of a primary side winding of the transformer andto ground, the controller senses a current level of the primary sidewinding of the transformer and operates the transformer regulationswitching device to regulate the transformer as a function of a sensedcurrent level of the primary side winding of the transformer.
 15. Amethod in accordance with claim 14, wherein the plurality of voltagereduction circuit cells includes a first voltage reduction circuit celland a second voltage reduction circuit cell coupled together in seriesbetween the input terminal and the output terminal, the first voltagereduction circuit cell being coupled to the input terminal, the secondvoltage reduction circuit cell being coupled to the output terminal. 16.A method in accordance with claim 15, wherein the first voltagereduction circuit cell is regulated at a first capacitive gain setting,the second voltage reduction circuit cell is regulated at a secondcapacitive gain setting that is different from the first capacitive gainsetting, the first capacitive gain setting having a voltage divisionratio that is less than a voltage division ratio of the secondcapacitive gain setting.
 17. A method in accordance with claim 14,including the steps of: determining a gain setting for each of theplurality of voltage reduction circuit cells as a function of thevoltage level of the input power signal and a predefined output signalvoltage level; and generating and delivering a control signal to each ofthe voltage reduction circuit cells as a function of the correspondinggain settings.
 18. A method in accordance with claim 17, wherein theplurality of voltage reduction circuit cells includes a regulatedvoltage reduction circuit cell coupled to the output terminal fordelivering the output power signal to the output terminal, the methodincluding the steps of: sensing a voltage level of the output powersignal; and regulating the control signal delivered to the regulatedvoltage reduction circuit cell as a function of the voltage level of theoutput power signal, the controller configured to adjust a duty cycle ofthe control signal to adjust the gain setting of the regulated voltagereduction circuit cell to maintain the voltage level of the output powersignal at the predefined output signal voltage level and a desiredoutput current level.
 19. A method in accordance with claim 18,including the steps of: determining a voltage level of the input powersignal; determining a predefined output signal voltage level and thedesired output current level; determining a required number of voltagereduction circuit cells to deliver the output power signal at a voltagelevel approximately equal to the predefined output signal voltage levelas a function of the voltage level of the input power signal and thedesired output current level; selecting an input voltage reductioncircuit cell of the plurality of voltage reduction circuit cells as afunction of the determined required number of voltage reduction circuitcells; determining a gain setting of each of the required number ofvoltage reduction circuit cells as a function of the predefined outputsignal voltage level; generating and delivering a control signal to eachof the required number of voltage reduction circuit cells as a functionof the corresponding gain settings; selecting at least one bypassvoltage reduction circuit cell of the plurality of voltage reductioncircuit cells as a function of the required number of voltage reductioncircuit cells; and operating the at least one bypass voltage reductioncircuit cell to deliver the input power signal to the input voltagereduction circuit cell including operating the switching circuit of theat least one bypass voltage reduction circuit cell in a bypass mode tocouple the positive plate and the negative plate of the first capacitorto each of a cell input terminal and a cell output terminal of the atleast one bypass voltage reduction circuit cell to short the firstcapacitor and to disconnect the second capacitor from each of the cellinput terminal, the cell output terminal, and the first capacitor,wherein the source and drain of the switching devices associated withthe first capacitor are shorted in parallel.
 20. A method in accordancewith claim 14, the method includes the steps of: selecting an outputvoltage reduction circuit cell from the plurality of voltage reductioncircuit cells as a function of a predefined output signal voltage level;and operating the selected output voltage reduction circuit cell tocouple the output voltage reduction circuit cell to the forward convertto deliver the intermediate power signal from the output voltagereduction circuit cell to the forward converter.
 21. A method inaccordance with claim 14, wherein the plurality of voltage reductioncircuit cells including a first set of voltage reduction circuit cellsand a second set of voltage reduction circuit cells coupled between thefirst set of voltage reduction circuit cells and the output terminal,the first set of voltage reduction circuit cells being coupled togetherin series, the second set of voltage reduction circuit cells beingcoupled together in parallel.
 22. A method in accordance with claim 14,wherein the electrical circuit further includes a buck regulator circuitcoupled between the input terminal and the output terminal, the methodincluding the step of operating the buck regulator to deliver the outputpower signal to the output terminal if a current level of the outputpower signal is larger than a predefined current level.
 23. A method inaccordance with claim 22, wherein the forward converter is coupled tothe buck regulator circuit, the plurality of voltage reduction circuitcells, and the output terminal for delivering power signals from thebuck regulator and the plurality of voltage reduction circuit cells tothe output terminal.
 24. A method in accordance with claim 14, whereinat least one of the plurality of voltage reduction circuit cellsincluding an inductor and a diode coupled to the switching circuit andthe hold capacitor, the method including the step of operating the atleast one voltage reduction circuit cell as a buck regulator circuit fordelivering the output power signal to the output terminal.
 25. Anapparatus for providing electrical power for use in powering electronicdevices, including: a plurality of semiconductor chips, each of theplurality of semiconductor chips including a voltage reduction circuitcell including a plurality of capacitor terminals and a switchingcircuit including a plurality of switching devices coupled to theplurality of capacitor terminals, the plurality of semiconductor chipsincludes a first semiconductor chip including an input terminalconfigured to receive an input power signal and a second semiconductorchip including an output terminal configured to provide an output powersignal, the plurality of voltage reduction circuit cells being coupledtogether in series between the input terminal and the output terminalfor delivering the output power signal at a voltage level that is lessthan a voltage level of the input power signal; a plurality of flybackcapacitors coupled to each of the plurality of capacitor terminals, theplurality of capacitor terminals including a first set of capacitorterminals coupled to a first flyback capacitor, a second set ofcapacitor terminals coupled to a second flyback capacitor, and a thirdset of capacitor terminals coupled to a hold capacitor, thecorresponding plurality of switching devices including a first switchingdevice for coupling a negative plate of the first flyback capacitor toground and a second switching device for coupling a negative plate ofthe second flyback capacitor to ground, at least one of the plurality ofswitching devices coupled between the hold capacitor and the first andthe second flyback capacitors; a forward converter coupled to theplurality of voltage reduction circuit cells for receiving anintermediate power signal from the plurality of voltage reductioncircuit cells and delivering the output power signal to the outputterminal, the forward converter including a transformer and atransformer regulation switching device coupled to a bottom end of aprimary side winding of the transformer and to ground; an input voltagesensing circuit configured to sense a voltage level of the input powersignal; a current sense circuit configure to sense a current level ofthe primary side winding of the transformer; and a controller configuredto: determine a gain setting for each of the plurality of voltagereduction circuit cells as a function of the sensed voltage level of theinput power signal and operate each voltage reduction circuit cells atthe corresponding determined gain setting; and operate the transformerregulation switching device to regulate the transformer as a function ofthe sensed current level of the primary side winding of the transformerto deliver the output power signal at the predefined output signalvoltage level.